Just finished an LS3 crate motor swap on a buddies car. Had to swap one sensor, and dropped it right in. Stock heads, cam, and all. We did add a B&M flexplate and 3200 Circle D stall. Other mods were already on the car. VR, PaceSetters, 2.5 exhaust, 3.45 gears, BMR suspension, and me tuning it. Previous best with bolt-on L76 was 12.6x @ 113. New motor has less than 1K miles on it. Went 12.0x three times in a row, and then 11.97!! Pretty damn happy about that.