C10 LS Swap Checklist (1973–87 Square Body)
A 1973–87 square-body C10 has room for any truck LS. A junkyard LQ4 6.0 with a 4L80E comes to about $7,570 with used parts and your own labor, or about $14,445 new with shop labor.
Three C10 builds, priced
| Build | Crank | Wheel | 1/4 mile* | Used parts, DIY | New parts, shop | |
|---|---|---|---|---|---|---|
| LQ4 6.0, stock, 4L80E | 335 hp | 275 whp | 13.51s | $7,570 | $14,445 | Open |
| LM7 5.3, Stage 2 cam, 4L80E | 375 hp | 308 whp | 13.01s | $8,395 | $16,963 | Open |
| LQ4 6.0, Stage 3 cam + turbo 12 psi, TH400 | 701 hp | 575 whp | 10.56s | $13,783 | $27,893 | Open |
The C10 LS swap checklist
- Engine mounts. Dirty Dingo, Hooker and CPP all make square-body mounts (Dirty Dingo's 2WD part is DD-2500C).SummiteBayAmazon
- Transmission crossmember for your transmission: Hooker BHS500 (4L60E, 4L80E, 6L80E, T56) or Dirty Dingo's adjustable one.SummiteBayAmazon
- Oil pan. 4WD trucks need a 4WD swap pan such as the Holley 302-4. For 2WD, Speedway lists the 302-1; check yours against the crossmember.SummiteBayAmazon
- Fuel system: an in-tank or EFI-rated pump holding about 58 psi, plus a filter/regulator and -6AN adapters.SummiteBayAmazon
- Wiring and computer matched to your engine's 24x or 58x crank trigger.SummiteBayAmazon
- Gauge cluster. The factory cluster may need wiring changes or adapters to read LS oil pressure and temperature.SummiteBayAmazon
- Speedometer fix. Square bodies have a cable speedometer; a Dakota Digital ECD-100 drives it from the LS transmission's signal.SummiteBayAmazon
- Driveshaft shortened or new, with the right yoke (4L80E/TH400: 32-spline).SummiteBayAmazon
- Cooling: radiator and electric fans sized for the LS, plus a steam tube kit.SummiteBayAmazon
- Rear end. Half-tons mostly have an 8.5-inch 10-bolt, commonly run to about 450 hp on street tires. Past that, a 12-bolt or 9-inch.
The 701 hp turbo build is well past the 8.5's comfort zone. The calculator marks the rear axle upgrade as recommended, so it isn't added to the total unless you choose it.
Sources
- PSI Conversion: Squarebody LS swap parts
- JEGS: Holley 302-4 4WD LS swap oil pan
- Speedway Motors: LS swap parts table
- GMSquarebody: rear end and gear suggestions
- Chevy Hardcore: Dakota Digital ECD-100
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