The motor in the srt8 is a 6.1, they bore and stroke it to a. 7 litre. The motor is a roloer can, stage 4 heads, supercharged 12 lbs of boast, and some otherbgoodies like pistons and so on. Check there website, shophemi.com..The car is a freaken rocket, dynoed 750lbs of tourqe at 3500 rpms...At 6000 rpms rwd dyno at 716..here's the best part, a few months ago I drove it on the turnpike 120 miles one way at 70 MPH in 6th great at 2000 rpms and got 23.7 MPG?