What is involved in swapping an LS2 with a 6L80E into a 2001 4.8/4L60E Silverado, including electronics, fitment, and driveshaft changes?

An LS2/6L80E swap into a 2001 4.8/4L60E Silverado is well within reach if you plan the electronics and driveshaft up front. To keep the truck accessories, swap on a truck harmonic balancer so you don't need custom power steering and A/C lines, and replace the Corvette LS2 intake with a truck (TBSS) intake for clearance. The 6L80 uses the same style rear mount but sits slightly rearward, so modify the stock crossmember; its extra bulk is below the mainshaft centerline, so tunnel clearance is fine. The 6L80 is shorter than a 4L60E, so you'll need a longer driveshaft, and keep in mind a 6L90 is 35mm longer than a 6L80. For electronics, what we've seen work is a custom harness (such as the Speartech harness) with an E38 running the engine and trans, an electronic throttle pedal, and a mini-harness that keeps the old PCM so the gauges and A/C still work. In one build we've seen, a stock LS2/6L80 with stock manifolds and converter ran 13.67 @ 101 mph.

Check this first:

• Measure for the longer driveshaft (6L80 vs 6L90 length differs by 35mm)
• Check intake clearance and swap to a truck (TBSS) intake
• Plan the mini-harness so the old PCM still runs gauges and A/C
• Fit an electronic throttle pedal

Based on what we've seen work across our own builds, our friends' builds and the wider LS community, reviewed by our lead tuner (20 years of LS tuning). Every combination is different, so use at your own risk and check our safe tuning limits before any wide-open pass.