Well., I finally finished crunching the numbers for my LS4 in a Chassis Works chassis. I am making the bottom subframe/engine cradle 11 inches wider, and the top section of the rear subframe 2 inches wider. This will give me 1 inch of engine clearance for the trans and engine on top. I am modifying the chassis so the lower section/engine cradle and suspension will unbolt, and removed from the bottom, just like a front wheel drive car. Because the lower control arm is 5.5 inches shorter, I think that progressive springs are in order. With the lower control arms shorter, the leverage/lever factor on the coil overs changed. I don't think 400lb springs are needed, the ride would be too hard. I am using factory rubber drivetrain mounts. I don't want to feel drive train vibrations.What do my lambo brothers think? I will be posting pics soon.