SBC 350 to LS Swap in Square Body – What You Need

If you’re pulling the 350 out of your 73–87 C10 and dropping in an LS, you’ve made a great choice. The LS is lighter, more powerful, and more reliable. Here’s your complete parts checklist.

Why Swap the SBC 350 for an LS?

  • The LS makes more power from the factory
  • Better fuel economy (EFI, tighter tolerances)
  • Stronger bottom end
  • Excellent aftermarket support
  • Can retain AC, power steering, and accessories

Engine Options:

  • LS1 5.7L (1997–2004 F-body, Corvette) – Most popular, great power potential
  • LQ4 6.0L (truck engine) – More torque stock, iron block, cheaper
  • LQ9 6.0L (truck engine) – Comes with LS2 rectangular port heads
  • LM7 5.3L (truck engine) – Most common and cheapest LS to find

What You Need for the Swap:

Engine Mounts:
1973–1987 C10 LS Swap Engine Mount Kit – 2WD/4WD – Welds to the factory frame pads and accepts LS engine mount ears.

Transmission:
The LS mates easily to:

  • 4L60E (bolt-in with no crossmember changes on most C10s)
  • 4L80E (requires crossmember modification)
  • T56 manual (requires tunnel modification)
  • 700R4 (adapter required)

Wiring:
A standalone LS harness is the cleanest solution. See our wiring guide in the forum.

Fuel System:
You’ll need to convert to EFI fuel system:

  • In-tank or inline EFI fuel pump (58–62 PSI rated)
  • Return or returnless fuel system
  • Fuel pressure regulator

Accessories:
The LS accessory drive (AC, power steering, alternator) is a different configuration from the SBC. Budget for a new accessory bracket kit or a serp belt conversion.

Exhaust:
LS headers for the C10 are widely available. Full-length Hedman or Hooker headers are popular choices.

Total Budget:

  • Engine (junkyard): $500–$2,000 depending on mileage and source
  • Complete swap parts (mounts, harness, fuel system): $1,000–$2,500
  • Professional labor: $2,000–$5,000

What LS engine did you use in your C10? Share your build notes below!