Thanks insidious for the comments
I'll need to have tinted windows anyway, because I am sensitive to the light and it gives me migraines.
As far as the engine, the Olds 455 big block makes tremendous torque with minimal modifications. A bone stock 455 with 10:1 compression and stock camshaft makes 350HP and up close to 450 ft lbs of torque at low rpm, so it's the perfect engine for a heavy truck (plus it was all free)
I want to lower it too, but I do not want to cut the frame for a C notch or anything like that, because I want to keep the frame intact. I'd like a nice coil over suspension front/rear though