Engine

Intake, carb vs EFI, fuel system & fuel cell

Core call unchanged: Edelbrock Air-Gap 7561 dual-plane, with a fuel system built once for carb now and EFI later. The fuel hardware is corrected. A 1977 short bed uses the Tanks Inc TM11A-T ($300) or the Holley 19-454 kit, with the return-style Holley 12-136 module ($675.95) and an Aeromotive A1000 carb regulator…

Research note: many vendor pages (Summit, JEGS, Holley.com, CJ Pony) returned HTTP 403 to direct fetch, so most prices below come from search-result snippets and retailer listings, labelled "checked 2026-10-12". Snippet prices are not cart-verified; re-price at order time. Anything marked "NC" = not confirmed.

The pick

Good
~$1,900-2,000 (Air-Gap 7561 $439 + Street Avenger 770 $629 + Tanks Inc TM11A-T $300 + Holley 12-129 $416 (carb-only) + 4021 block-off + lines)
Better
~$2,700-3,600 (carb + 12-136 return module + A1000), or ~$3,700-4,500 on the Sniper 2 path
Best
~$4,400-4,700 (Air-Gap + Terminator X Max Stealth 4150 w/ trans control 550-1013 at $2,500 + Holley 19-454 tank kit at $1,066 + lines)
  1. Intake: Edelbrock Performer RPM Air-Gap 7561 (oval port) if heads are oval or Edelbrock Performer RPM aluminum heads. Single-plane Victor Jr. is the wrong tool for a power-brake, 65-70 mph commuter.
  2. Fuel system, build once for carb now / EFI later:
    • In-tank return-style 255 LPH module (Holley 12-136, $676) with HydraMat/baffle, in a baffled replacement tank. For a 1977 short bed that is the Tanks Inc TM11A-T ($300) or the Holley 19-454 kit ($1,066, includes its own pump). Do NOT use the returnless Holley 12-129 here - it cannot be converted to EFI later. For a long bed (131.5 in. wheelbase, 8 ft box) a different tank applies (integration pass, search summaries only): Tanks Inc TM1A (20 gal, 56 x 14-1/8 x 11, frame-mounted in the original location, $170) and TM1A-T EFI tank kit ($621.95 per efisystempro; includes pump per the listing, verify), Holley 19-455 (the long-bed counterpart of the 19-454; price not confirmed), Performance Online 20-gal long-bed tank; CJ lists a 20-gal long-bed 1973-81 tank FT69 and a 25-gal long-bed 1973-80 tank behind the axle FT98, so read the tank sticker and measure which one the truck has. The brake line kit, bed floor and driveshaft also branch on bed length (see section 90, section 2.14).
    • -6 AN (or 5/16-3/8 hard) feed and a -6 return from the start.
    • Mechanical pump deleted with Edelbrock 4021 block-off.
    • External A1000 carb regulator (13201) now with the return line; change to the EFI regulator (13101) or use the Sniper/Terminator's internal regulator later.
    • Keep the module in the tank (not an external pump): general EFI practice, since in-tank cooling and push-not-pull avoid vapor lock near headers. (The earlier draft cited a FABO thread as showing external-pump hot-restart trouble; on fetch that poster used an in-tank Holley module and the cause was a pinched starter wire. Citation removed.)
  3. Carb vs EFI depends on the transmission:
    • TH400 or T56: Edelbrock AVS2 800 (1913) is a valid first choice and the cheapest path; TH400 needs only a full-throttle electric kickdown switch (B&M 20297 or Lokar style) (73-87.com).
    • 4L80E: go EFI, Holley Terminator X Max Stealth 4150 with trans control (550-1011/-1012/-1013, VERIFIED to control pre-2009 4L60E/4L80E; 4L85E not listed - confirm), because the alternative is carb + TPS + Holley VK102405 standalone controller, i.e. two boxes and more wiring for a teen to debug.
  4. EFI vs carb for Walter: EFI wins for cold start, altitude/temp and a teen who will not fiddle with chokes; carb wins on repairability with a screwdriver. A 4150 TBI keeps both options open: same flange, same manifold, same hood height.
  5. Not-yet-priced alternatives a square-body builder would expect: Edelbrock Pro-Flo 4 port EFI (35830 / 35840) and FAST EZ-EFI 2.0 + MSD Atomic TCM. A 4150 throttle body keeps the Air-Gap and a stock-looking engine bay; port EFI is the more powerful but taller, pricier route. TH400 note: the TH400's vacuum modulator needs manifold vacuum, so cam choice (idle vacuum) still matters with either carb or EFI.
  6. Choose the 800 over a 770/670 only if the engine is the Path A build; for Path B (400-450 hp) a 750 or 770 is enough.

Why it matters

The '77 C10 with a Mark IV 454, TH400 and a 35-minute interstate commute is the classic case where induction choice drives everything downstream: hood clearance, transmission control, the fuel system, and what a 16-year-old (Walter, ~2042) can diagnose. The engine goal (93-octane, 9.2-9.3:1 static per section 90 - the owner's original 10.3-10.5:1 was lowered for a truck cam - aluminum heads, powerband to 5,500-6,000, mean-but-streetable idle) points to a dual-plane manifold with a long-runner Air-Gap style design for the street path, and a 4150-flange carb or 4150-flange throttle-body EFI. Both fit the same manifold, which is the key to "carb now, EFI later."

The fuel system is the part that should be built once. The factory system is a 1977 frame-side tank, rotted steel lines, a mechanical pump on the block and (on a truck that sat ~10 years) varnished fuel. The owner already plans an electric pump and deleting the mechanical pump. If the in-tank pump, return line and large-bore feed are done right, the carb-to-EFI change later is a regulator swap plus a throttle body, not new plumbing.

Transmission matters: a TH400 needs only a full-throttle kickdown switch (no EFI interaction). A 4L80E/4L85E needs throttle-position input; carb + 4L80E requires a standalone controller with a TPS on the carb. A T56 Magnum has no controller dependency. So the 4L80E choice tilts toward EFI (one box does both).

Options

Intake manifold (Mark IV oval-port assumed; stock 454 heads are oval, but the manifold MUST be chosen to match whatever aluminum heads are bought - rectangular-port heads need a rectangular-port manifold. Verified: Weiand Stealth 8019 is the OVAL-port part; 8018 is the rectangular-port Stealth)

Tier Brand & model Part # Price (vendor, 2026-10-12) Link Notes
Good Edelbrock Performer RPM Air-Gap 2-O, standard finish 7561 ~$438.95 JEGS (search snippet, checked 2026-10-12); other resellers $460-520 JEGS Dual plane, 1,500-6,500 rpm, Air-Gap isolates charge from lifter-valley heat. Edelbrock's published fitment is "large oval-port heads (1975 and earlier) or Edelbrock Performer/Performer RPM heads"; it will not clear the stock hood on a Corvette/'64-67 Chevelle/'67-81 Camaro (a full-size truck hood is not on that list, but still mock up). Square-bore (4150) carbs only; no exhaust-heated choke provision (use an electric-choke carb). For a stock 1977 454 head, the port pattern is the same large oval that Edelbrock's '1975 and earlier' wording is describing in practice, but this was NOT confirmed - read the head casting number or buy the manifold to match the aluminum heads you choose.
Better Same, Chrome Plasma 7561-CP price not confirmed (the one price found was from an Australian site, currency unverified) Hurrey's Off-Road listing Finish only. Not needed for function.
Best (looks) Same, Black Plasma 7561-BP $678.95-$688.95 (CompCams / JEGS snippets 2026-10-12); Summit lists it but "not available at this time" JEGS Same casting.
Alt (not recommended) Edelbrock Victor Jr. 454-O single plane 2904 price NC JEGS Competition manifold, 3,500-7,500 rpm; sacrifices idle/low-end vacuum. Wrong for a 65-70 mph commuter that must also run power brakes.
Alt Weiand Stealth (oval-port 8019; rectangular-port is 8018) 8019 / 8018 price NC OPGI Dual plane high-rise, idle to ~6,800. The earlier draft called 8019/8021 rectangular-port; the OPGI URL and descriptions say 8019 is oval-port. (8021 not verified at all - dropped.) Taller than the Air-Gap's profile; hood clearance NC.

Holley Strip Dominator: street-unfriendly, skipped. Brodix intakes: not researched; price NC.

Carburetor (4150 flange)

Tier Brand & model Part # Price Link Notes
Good Holley Street Avenger 670 0-80670 price not separately confirmed (the $628.95 holley.com sale / $699.95 list figure found on 2026-10-12 was for the 770; 670 is typically a bit less) Holley Vacuum secondaries, electric choke, quick-change. 670 cfm is small for a 500 hp 454.
Better Holley Street Avenger 770 0-80770 $628.95 holley.com sale (list $699.95); Butler $626.95; Walmart $716.95 (search snippets 2026-10-12) Holley Better CFM match; verify price.
Better Edelbrock AVS2 650 1906 (electric choke, satin) US price not confirmed; JEGS 1906-BP black plasma $629.95 (snippet). The earlier "$470 eBay" is unverified. Remanufactured manual-choke 1905 $363.95 JEGS O'Reilly list Owner happy on stock-ish 454 per forum.
Best (carb) Edelbrock AVS2 800, electric choke (1912 is the manual-choke version) 1913 $569.95 JEGS and Speedway Motors; $514.99 OPGI; $581.72 Walmart (snippets 2026-10-12) Summit search Owner's lean pick. AVS2 is simple to tune; strong street reputation.

Throttle-body EFI (4150 flange)

Tier Brand & model Part # Price Link Notes
Good FiTech Go EFI 4 (600 hp) e.g. 30001/30002K, FF31002 master kit w/ inline pump price NC; JEGS shows discontinued, others in stock Classic Industries Holley owns FiTech; supply inconsistent. 600 hp NA ceiling is tight for 520 hp. Not recommended for a 20-year build.
Better Holley Sniper 2 EFI 4150 550-510-5XD returnless drop-in module ($1,911.95, was $2,249.95); 550-510-5XR return-style drop-in module ($1,911.95); 550-510-5XK inline pump ($1,741.95); 550-510-3PK w/ PDM + inline pump master kit ($1,999.95) JEGS, search snippet 2026-10-12. The earlier-draft figures ($1,549.95 / $1,749.95 / $2,049.95) are not current. JEGS Self-tuning, up to ~650 hp NA, internal regulator (returnless-capable at ~58 psi). Sniper Stealth 4150 (550-871) listed ~$1,483.95, Master Kit 550-871K ~$1,799.95 (Walmart).
Best Holley Terminator X Max Stealth 4150, 4 injectors, with trans control 550-1011 (shiny) / 550-1012 (black) / 550-1013 (gold), all 4-injector, 650 hp NA with 4L60E/4L80E trans control. SKU map (integration pass, from SD Parts' fetched 550-1013 page plus search summaries of Holley, JEGS and efisystempro listings; Holley's own pages return 403): 550-1011/-1012/-1013 = Stealth 4150, 4 injectors, trans control; 550-1014 (shiny) / -1015 (black) / -1016 (gold) = the same with 8 injectors, 1,250 hp, listed as discontinued products on holley.com; 550-917 and 550-920 = Terminator X Max for LS-family engines (24x/58x crank reluctor), $1,999.95, NOT for a Mark IV; 550-928 is the LS DBW kit in the next row. 550-1013 $2,499.95 (MSRP $2,812.95), special order at SD Parts, 2026-10-12. The earlier "$2,158.95" came from Billy's Speed Shop, a UK shop pricing in GBP, and is not a US price. The 8-injector 550-1014/-1015/-1016 versions are discontinued and not needed. The Stealth 4150 uses an external regulator (58.5 psi): Holley 534-237 crossover kit (billet regulator preset to 58.5 psi, bracket, braided crossover hose, bowl standoffs; JEGS/fpautoparts search summaries; price not confirmed) belongs in the BOM and needs a return line to the tank. Whether the 550-1013 box includes the 4L80E trans harness (BPP558405, $299.99 in section 16) is not confirmed: ask Holley. SD Parts Self-learning ECU with touchscreen. VERIFIED: the 550-1011/-1012/-1013 variants provide transmission control for pre-2009 GM 4L60E/4L80E, plus kickdown for TH350/400. The base Terminator X Stealth 4150 (550-1001) has kickdown only, no 4L80E control. 4L85E is NOT listed by Holley (4L85E is the 2008+ revision of the 4L80E hardware - confirm before buying); a TH400 owner does not need the trans-control version.
Alt Edelbrock Pro-Flo 4 EFI (multi-port, BBC oval port) 35830 (4150-style single-plane intake, 35 lb/hr, 550 hp) $2,365.95; 35840 (sequential, 60 lb/hr, 850 hp) $2,700.68 snippets 2026-10-12; 35840 also seen at $3,887.93 elsewhere Fass Motorsports A missing-option add: true port injection, ships with its own intake. Page 404'd on re-fetch, so treat part numbers/prices as snippet-level. Tall; single-plane-style manifold gives up the Air-Gap's low-end vacuum, so power-brake/booster check needed.
Alt FAST EZ-EFI 2.0 self-tuning 4150 throttle body 30400 base kit $2,939.95 (snippet) CompCams Well-established alternative to Sniper/Terminator X; pair with MSD Atomic TCM ($949.95, plugs into 4L80E connectors) for trans control. Not hand-verified for the 454 here.
Alt Terminator X Max (LS-type harness) 550-928 ~$1,999.95 w/ 4L60/80E control JEGS LS-engine kit, not for a Mark IV; mentioned only for the X Max trans control.
Alt Holley standalone trans controller (carb + 4L80E), GM 4L60/80E, with 3.5" handheld VK102405 $1,005.90-$1,118.90 (holley.com snippets 2026-10-12) Holley Needs TPS on the carb (Holley TPS kits 534-202 for Holley carbs w/ electric choke, 1951 for Street Demon).

Aftermarket EFI manifold for TBI on a 454: Holley sheet-metal fabricated Sniper manifolds exist for BBC (HL835061, HL835171 via CJ Pony) - not needed; the Air-Gap works for TBI.

Fuel tank

Tier Brand & model Part # Price Link Notes
Good Tanks Inc. 1973-81 EFI gas tank, 6' short box, 16 gal TM11A-T $300.00 (Tanks Inc, fetched 2026-10-12) Tanks Inc THE correct tank for a 1973-81 short-bed C/K10: 42-7/8 x 14-1/8 x 11 in, frame-mounted ahead of the rear axle, EFI-style 4.8 L baffled sump, accepts GPA-series pumps (109-450 LPH) on a 5-bolt flange, silver powder coat, 1-1/4" filler. The earlier draft missed this and proposed 1982-87 tanks.
Good (cheap, non-EFI) Tanks Inc. 1973-81 6' box plain steel tank TM11-A (GM11A) $160.00; out of stock until late Oct (Tanks Inc) Tanks Inc No EFI baffling - fine only if you keep a low-pressure carb setup with a returnless-style retrofit module; also CJ Classic Trucks FT68 and Auto Metal Direct 890-4073-16 ($94.99, straps and sender sold separately) are 16 gal 1973-81 short-bed side tanks.
Does NOT fit a '77 Tanks Inc. TM11B-T (1982-87, 16 gal, ~$294.98) and TM1B-T (1982-91, 20 gal, ~$318.99) JEGS TM11B-T Wrong years; the GM 1982-87 tank (GM11B style) differs from the 1973-81 tank. Kept only so the earlier draft's references are traceable. Do not order for a '77. A 20-gal tank is the long-bed/'82+ part.
Good Spectra GM1C (20 gal long bed) / GM11C (16 gal short bed) listed by HotRodan price NC. NOTE: these are 1987-spec EFI tanks (HotRodan pairs them with FG05M/N senders) - 1973-86 tank fitment is not confirmed HotRodan guide EFI-ready baffled replacements.
Alt (caution) USA1 Industries 1987-style EFI tank 16 gal $129.95 (fetched; SKU 16418) USA1 Cheapest. It is a 1987 tank that USA1 says is compatible with EFI/TBI conversions of 1973-86 models; I could not confirm that it bolts into a 1973-81 frame. Prefer the Tanks Inc 1973-81 part. 20 gal $119.95 price was not re-verified.
Better Holley Sniper EFI tank kit, 1973-81, 6 ft bed, 400 LPH 19-454 (system); Eckler's 61-884614-1 $1,065.95 (Eckler's, out of stock at fetch 2026-10-12; MSRP $1,153.95; as low as $921.95 elsewhere, snippet) Eckler's Direct fit, no drilling, 16 gal baffled galvanized steel, 4.3 L tray, sender calibrated for factory gauge. Strongest "bolt-in, 1973-81 truck" option found.
Best Performance Online 19-gal aluminum tank (rear mount, between frame and behind axle) combo kits available price NC POL Moves tank out of cab; needs bed-fill filler. Also forum builds use Blazer/Suburban 25-31 gal tanks (gmsquarebody).

Pump / module

Tier Brand & model Part # Price Link Notes
Good (carb-only) Holley in-tank carb retrofit, 255 LPH, returnless (low pressure) 12-129 $415.95 (NAPA, fetched 2026-10-12); $399.95 Butler snippet NAPA ~6 psi, up to 700 carb hp, HydraMat, UNIVERSAL 5" flange module for 6.5-12 in. deep tanks (not a 1973-87 direct-fit sender). Pump is Walbro GSL392 class. Carb only: it is a dead end for the 'build once, EFI later' plan, because the Sniper/Terminator need ~58 psi. Do not combine it with an A1000 regulator (it is already regulated and has no return). Confirm how its 5" flange mounts in a Tanks Inc 5-bolt-opening tank before buying.
Better (EFI, returnless, factory-tank) Holley EFI module for C10 1973-87 (255 LPH, internally regulated at 58 psi, HydraMat, sender 0-90 ohm) 12-308 (also CJ Pony FP90) price NC CJ Pony OEM-style sender + pump; return not required. VERIFIED: direct replacement for the factory pickup/sender, rated to ~500-550 hp, intended for 1973-86 tanks WITHOUT the GM11B-style EFI baffles - i.e. stock-style tanks, not the Tanks Inc TM11A-T EFI tank or a Holley kit tank (which have their own pump hangers). Shown in Holley blog.
Better (the true build-once-carb-then-EFI part) Holley retrofit module 255 LPH WITH return, for tanks 7-12 in. deep 12-136 $675.95 (NAPA / CJ Pony, snippets 2026-10-12) CJ Pony Return-style = works for carb with external regulator AND EFI.
Best Aeromotive Phantom 340 (return style) 18688 universal; carb kit 17254 / 7254 variants $1,720.22 (Aeromotive.com carb kit 17254, fetched 2026-10-12; the earlier $1,534.95 was stale); 18688 alone price NC Aeromotive Fits 6-11" deep tanks; return style only; 340 LPH; carb or EFI. Prices from snippets look high; kits vary in contents - verify.
Regulators Aeromotive A1000 carbureted bypass regulator (3-15 psi) = 13201; A1000 EFI regulator (40-75 psi) = 13101, $243.23 on Aeromotive.com (fetched 2026-10-12). 13301 is the UNIVERSAL bypass regulator (3-20 psi std spring, 20-60 psi high-pressure spring included), not the A1000 carb part as the earlier draft said 13201 / 13101 / 13301 price for 13201 NC Aeromotive A 13301 universal regulator can serve both carb and EFI with a spring swap. Swap regulator when going EFI. Holley Sniper has an internal regulator (a forum poster on a 1983 K10 350 quoted ~120 psi max inlet; Holley's own spec is a 58 psi system, gmsquarebody).
Block-off Edelbrock BBC fuel pump block-off plate 4021 price NC CJ Pony Fits Mark IV 396-502. Billet, gasket + bolts.
Lines PTFE-lined braided -6 AN or hard line -6 feed and return (0.320" ID, good to ~650 hp) $110-$170 for 20-30 ft bundles HotRodan Hard line along frame, braided PTFE only at engine/tank flex points (Dragzine).

Cost roll-up (induction + fuel, owner labor)

Good Better Best
Path Perf RPM Air-Gap ($440-460) + Street Avenger 770 ($629) + Tanks Inc TM11A-T 16 gal ($300) + Holley 12-129 ($416, carb-only) + 4021 block-off ($32) + hard/PTFE lines ($250) Perf RPM Air-Gap + Edelbrock AVS2 800 ($570) + Tanks Inc TM11A-T ($300) + Holley 12-136 return module ($676) + A1000 13201 regulator + lines; or Sniper 2 (~$1,740-1,910) + 12-308/Tanks tank Air-Gap + Terminator X Max Stealth 4150 w/ trans control (550-1013 $2,500) + Holley 19-454 tank kit ($1,066; it includes its own 400 LPH pump, so no separate module) + lines
Approx. total ~$1,900-2,000 ~$2,700-3,600 (carb + return module) / ~$3,700-4,500 (Sniper 2 path) ~$4,400-4,700 (Terminator X Max + Holley tank kit + Air-Gap + lines)

(Estimates only; sums of snippet prices, re-derived 2026-10-12. The earlier draft's $5,500-6,500 Best total double-counted a separate pump module on top of the Holley tank kit and used a non-US Terminator X price. Carb + 4L80E alternative: Street Avenger/AVS2 ~$600 + VK102405 ~$1,000-1,120 + TPS kit lands within ~$0-100 of one Sniper Stealth ($1,484) + same controller, and about the same as a single Terminator X Max with trans control, so on a 4L80E truck EFI costs essentially nothing extra.)

Fitment & gotchas

  • Tank location: a 1973-81 short-bed C/K10 has a frame-mounted 16-gal side tank ahead of the rear axle (Tanks Inc TM11A-T/TM11-A, Auto Metal Direct, CJ Classic FT68, Holley 19-454 all say 1973-81 short box, 42-7/8 x 14-1/8 x 11 in; Holley and Auto Metal say it works on either side). The in-cab tank is a 1963-72 feature - the earlier 'in-cab' safety language below is not for this truck. Long-bed trucks differ (20 gal frame-mounted, or 25 gal behind the axle on 1973-80 per CJ FT98). Confirm bed length (wheelbase 117.5 in. short, 131.5 in. long) and read the tank sticker before ordering.
  • Pre-1987 stock tanks are unbaffled; EFI/hard cornering can starve a pump (HotRodan). Baffle is mandatory with an electric pump.
  • Sending units: Spectra FG05M (driver) / FG05N (passenger) per HotRodan (these are listed there for 1987-spec tanks; not confirmed for 1973-81). Keep tube material on hard-line adapters.
  • Dual tanks: need an EFI-rated selector valve; return must go to the same tank.
  • Mechanical pump delete: the block-off plate fits Mark IV; the old pump lever/pushrod hole should be sealed, not left to weep oil.
  • Filler routing: when relocating, 3-5 inches of fall per ~3 ft run and a proper breather (gmsquarebody).
  • Return line: the Holley kit supplies 20 ft of rubber hose; owners prefer steel return with a short rubber loop at the engine for torque movement.
  • Heat: an external pump close to headers is a classic hot-restart/vapor risk (general practice, not source-verified here). An in-tank module avoids it.
  • Hood clearance: not confirmed for Stealth 4150 with a 454 in this research. Measure with a mockup (manifold + carb/TB + air cleaner) against the hood and the power-steering/brake booster.
  • Voltage: pumps need 13.5 V at the pump. A 1977 harness is marginal; run a relay with a fresh 10-12 ga feed straight from the battery/alternator (what gmsquarebody owners did).

Safety of old tank removal:

  • Tank has been empty or sitting ~10 years: assume fumes. Disconnect battery, no sparks/grinders/heat, work outdoors, ground the tank, drain into approved container, plug lines.
  • Do not try to weld or cut an old tank without purging (steam/water fill). Buy new instead.
  • Replace all rubber hoses and the rotted steel line to the engine.

How it touches other systems

  • Transmission: TH400 = kickdown switch; 4L80E/4L85E = TPS-based trans controller (Holley VK102405 for a carb, or Terminator X Max with trans control); T56 = no interaction but needs a clutch/pedal/hydraulic setup outside this section.
  • Cam/power brakes: a hotter cam lowers idle vacuum; the Air-Gap dual plane keeps more vacuum than single plane. Size cam and booster (or add vacuum pump/hydroboost) together.
  • Ignition: Sniper/Terminator X can control timing via the ECU; Edelbrock/Holley carb needs distributor curve work. Stock HEI works with either.
  • Exhaust/headers: pump and fuel lines must stay clear of long-tube headers and X-pipe.
  • A/C: A/C box on 1973-87 trucks and big-block-heights vs. hood; manifold + TB must clear the compressor and brackets.
  • Wiring: a fused, relayed EFI/pump power circuit with oil-pressure safety switch; the owner is comfortable with wiring.
  • Cooling: heat soak is a factor on carb and TB alike; Air-Gap helps.
  • Rear gear/converter: not fuel-related; but ignition/EFI trim should be tuned once final gear/converter chosen.

Check on the truck

  1. Where is the tank and what year/code? Photograph the tank and filler path. Single or dual tank?
  2. Which heads: stock oval, aluminum oval, or rectangular? (decides manifold)
  3. Which transmission (TH400 vs 4L80E vs T56) - the single biggest driver of carb vs EFI.
  4. Tolerance for a touchscreen/laptop-tuned ECU vs. a carb? Who will maintain it when Walter drives?
  5. Hood clearance: stock hood or new? Air cleaner height wanted?
  6. Willing to cut/weld for a frame-rail or bed-fill tank, or prefer bolt-in?
  7. Which car AC/compressor and which power steering pump (bracket clearance)?

Fact-check notes

Adversarial pass, 2026-10-12. Original saved in the scratchpad as 04-induction-fuel.orig.md.

Fetched live or searched and confirmed (about 30 URLs touched): Tanks Inc TM11A-T and TM11-A pages (200), Eckler's Holley tank kit (200), NAPA 12-129 (200), Aeromotive 17254 and 13101 (200), SD Parts 550-1013 (200), Billy's 550-1001 (200, but UK/GBP), USA1 (200), Auto Metal Direct (200), HotRodan (200), 73-87.com (200), Dragzine (200), gmsquarebody 776328 and 643546 (200), FABO (200), plus ~25 search-result pages for prices. Dead or wrong: m.reach.dog 7561 (301 then HTTP 410 Gone) replaced; Eagle Auto Parts link is an Australian site, price/currency unverifiable, replaced; Billy's Speed Shop prices were GBP, not USD. Walmart, Summit, JEGS, Holley.com, CJ Pony, OReilly, CompCams, ck5.com, Classic Industries returned 403/robot pages to the fetcher, so those links could not be opened (they appear in search results; ck5 thread and Holley VK102405 page content NOT confirmed). Fass Motorsports Pro-Flo and Fidanza 7561 pages 404'd on fetch.

Changed:

  1. Tank: a 1973-81 short-bed C10 has a frame-mounted 16 gal tank ahead of the axle (not in-cab). Added the correct Tanks Inc TM11A-T ($300), TM11-A ($160); marked the 1982-87 / 1982-91 Tanks Inc parts as not fitting; removed in-cab framing. Cost roll-up Good tier no longer uses the 20-gal 1982-91 tank.
  2. Pump: Holley 12-129 is a universal returnless ~6 psi carb module and cannot be converted to EFI later, which contradicted "build once". Recommendation now centers on the return-style 12-136 plus A1000 regulator; 12-308 confirmed as the stock-tank EFI direct-fit (58 psi, no return).
  3. Regulator part numbers: A1000 carb is 13201 (3-15 psi); 13101 is EFI ($243.23); 13301 is the universal regulator (draft had 13301 as the A1000 carb part).
  4. Terminator X: trans-control variants confirmed as 550-1011/-1012/-1013 (pre-2009 4L60E/4L80E; base 550-1001 is kickdown only); 550-1013 is $2,499.95, not $2,158.95 (UK price); 4L85E claim removed (not listed by Holley); 550-1016 is the discontinued 8-injector part.
  5. Sniper 2 prices updated to current JEGS figures ($1,741.95-$1,911.95); Phantom 340 kit now $1,720.22; Street Avenger 770 $628.95; AVS2 800 $514.99-$581.72; Air-Gap 7561 $438.95 at JEGS; VK102405 ~$1,006-1,119 now priced.
  6. Weiand Stealth 8019 is oval-port (8018 is rectangular); 8021 dropped as unverified.
  7. Air-Gap 7561 fitment caveat added: Edelbrock states large oval-port heads "1975 and earlier" or Edelbrock heads; a stock 1977 head match was not confirmed. Pick the manifold to match the aluminum heads chosen.
  8. FABO hot-restart citation removed: that thread's cause was a pinched starter wire on an in-tank module.
  9. Added missing options: Edelbrock Pro-Flo 4 port EFI (35830/35840), FAST EZ-EFI 2.0 (30400) with MSD Atomic TCM, and the TH400 modulator-vacuum/cam note.
  10. Cost-roll-up totals recomputed; the Best tier no longer double-counts a pump module with the Holley tank kit.

Recommendation: unchanged in spirit (Air-Gap 7561 + build-once return-style fuel system; carb with TH400/T56, Terminator X Max with trans control on 4L80E), but the fuel hardware is now the Tanks Inc TM11A-T or Holley 19-454 plus the 12-136 return module, not a 1982-87 tank plus the returnless 12-129.

Still unverified: hood clearance, Air-Gap fit on stock '76+ heads, whether Holley retrofit modules mate with the Tanks Inc TM11A-T opening, long-bed tank, A/C compressor bracket clearance, Terminator X on a 4L85E, whether the 550-1013 includes the 4L80E harness, the 534-237 price, and every price (snippet-level, not cart-verified).

Sources 35

  1. jegs.com (search result)
  2. summitracing.com (search result)
  3. jegs.com (search result; replaces reach.dog, which now returns HTTP 410)
  4. hurreysoffroad.com (search result; replaces an Australian-site link)
  5. jegs.com
  6. opgi.com
  7. summitracing.com
  8. oreillyauto.com
  9. holley.com
  10. holley.com
  11. classicindustries.com
  12. walmart.com
  13. billysspeedshop.com
  14. jegs.com
  15. holley.com
  16. holley.com
  17. hotrodan.com (fetched)
  18. gmsquarebody.com (fetched)
  19. gmsquarebody.com (fetched)
  20. ecklers.com (fetched)
  21. jegs.com
  22. jegs.com
  23. usa1industries.com
  24. performanceonline.com
  25. napaonline.com
  26. cjponyparts.com
  27. cjponyparts.com
  28. aeromotiveinc.com
  29. aeromotiveinc.com
  30. cjponyparts.com
  31. dragzine.com
  32. (removed: FABO thread did not support the claim it was cited for; see Verification notes)
  33. 73-87.com (fetched)
  34. ck5.com
  35. cjponyparts.com