Choosing the right LS swap engine mounts for your 73–87 C10 is critical to the success of your build. The mounts determine engine position, header clearance, and overall fitment. Here’s what to know.
Why Engine Mounts Matter in an LS Swap:
The C10 was designed around a small block Chevy (SBC) with different mounting ears. The LS engine family uses a different mounting hole pattern that is offset from the SBC pattern. LS swap mounts bridge this gap while positioning the engine correctly in the bay.
Engine Position Factors:
- Forward/Back: Affects firewall clearance for the intake manifold and headers
- Up/Down: Affects oil pan ground clearance and hood clearance
- Left/Right: Affects driveshaft angle and header-to-frame clearance
Best Engine Mount Option:
1973–1987 C10 LS Swap Engine Mount Kit – Fits 2WD and 4WD – These weld to the factory SBC frame pads and accept the LS bellhousing-style mount ears. Positions the LS in the stock SBC location.
Frame-Mount vs Rubber Mount:
- Frame weld mounts: Most solid, no flex, requires welding to the frame
- Rubber energy mounts: Reduces vibration, no frame welding needed
- Polyurethane motor mounts: Firmer than rubber, less vibration than solid
Clearance Issues to Check:
Before finalizing mount height, verify:
- Distributor/coil pack to firewall clearance
- Oil pan to crossmember clearance
- Header collector to frame clearance
- Intake manifold to hood clearance (may need hood scoop or hood modification)
Which LS Engines Fit:
Most LS engines (LS1, LS2, LQ4, LQ9, LM7, L33) fit the same basic footprint in a C10 with these mounts. The 4.8/5.3/6.0 truck engines are the most popular due to low cost.
Tips from Experienced Builders:
- Mock everything up in the engine bay before welding
- Use headers as a fitment guide before finalizing mount position
- The LS sits farther back and lower than the SBC in most applications
Share your LS engine and mount setup in your C10 below!