LS or EFI Swapping Your ’73–’87 C10 & K10 Squarebody: Fuel System Installation Guide
If you're building out a Squarebody Chevy or GMC LS engine swap or EFI conversion, this complete guide covers everything you need beyond our PTFE hose kits—fuel pick-up tanks, pumps, filters, regulators, tools, and installation best practices.
Fuel Tanks & Sending Units
- Tanks Inc EFI-ready squarebody tanks (use GPA4 pump for 255 LPH flow)
- Spectra Premium EFI tank: Long bed GM1C or short bed GM11C with internal baffle
- Blazer-style tanks: GM15C (25 gal), GM14C (31 gal) EFI-ready
- Spectra sending units FG05M/FG05N for pickups, FG12L/FG12K for Blazers—match tank and filler door location
Convert factory hardlines to AN6 fittings using:
- 5/16″ or 3/8″ hardline to AN6 adapter
- M14×1.5 or M16×1.5 to AN6 adapter for Blazer tanks
Fuel Pumps for LS Swaps
- Spectra Premium 190 LPH pump – ideal up to ~450 hp
- Walbro 255 LPH in-tank pump – supports modified LS engines up to ~700 hp
- Aeromotive 340 LPH Stealth pump – for high‑output builds
Fuel Line Kits & Hose Options
Choose depending on system type:
- Return-style LS swap: ~25–27 ft PTFE hose (30 ft kit commonly used)
- Returnless or EFI: ~20 ft PTFE hose if mounting regulator/filter close to tank
Select from these hose options:
- Nylon braided AN hose bundles
- Stainless braided AN hose bundles
- Color braided AN hose bundles
Filters & Regulators
- Return-style: Provide a post-pump inline 10‑micron filter—options include Holley or Aeromotive with required ORB‑to‑AN adapters
- Returnless setups: Use a Corvette-style filter/regulator (built-in AN6) set to ~58 psi. Our Return-Less kit includes this regulator—no extra filter needed.
Installation Tools & Wiring
- PTFE hose cutting shears
- Aluminum vice jaws and AN wrench set for fittings
- High-gauge wiring, proper relay, and dual-pump dash switch (e.g. DS283)
Installation Best Practices
- Install pump inside Spectra sending unit—remove bubble flares before installing adapters; do not cut vent without proper adapter.
- For returnless: orient the Corvette regulator with 3/8″ feed and 5/16″ return correctly; use adapter fittings built into Hot Rod AN kit.
- Route hoses inside frame rails with minimal sharp bends to protect lines.
- For dual-tank systems: convert both sending units and install switching valve with correct barb-to-AN adapters before routing fuel lines.
Fuel System Setup Summary
| Setup Type | Hose Kit | Filter / Regulator | Typical Pump Options |
|---|---|---|---|
| Return‑style LS swap | ~30 ft PTFE hose | 10 µ inline filter (Holley or Aeromotive) | Spectra 190, Walbro 255, Aeromotive 340 |
| Returnless LS or EFI swap | ~20 ft PTFE hose | Corvette-style filter/regulator (58 psi) | Spectra 190, Walbro 255, Aeromotive 340 |
Shop Fuel System Components
- Return-style LS swap kit
- Returnless LS swap kit
- AN PTFE hose & fitting bundles
- Corvette-style filter/regulator
- Spectra Premium sending units for Squarebody LS/EFI
Need Help?
If you have questions about hose routing or part compatibility, contact us via our Contact Us page or email info@hotrodfuelhose.com. We're here to help your swap go off without a hitch.
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