The sad truth? IE C10, G10*20. 84 as the sample (I believe 70's may show that the 10 was 4.75 wheel lug pattern and 154 pad, Remember they made early G20 6 lug much like the trucks!) Lower BJ 6117, upper 6136 all models, you will also see they use the same A3, A5 wheel bearing. The brakes will also work on many 70's to 80's cars, so yes if you see 71-76 impala you can use the rotors and calipers. Want to be weird try using mid 70's caddy rear caliper and add front parking brakes. Want just a 1 inch drop on the front end? use same 70+76 impala lower BJ and see what rubs. My brother just brought home a 66 C10 from the looks of it he could take my whole 89 G30 front end and go 8 lug! Some tweeks may be needed for the steering and sway bar? Only when you get to the 30 things start getting Heavy Chevy. My 89 is weird the frame rails are straight from the front door back, the front leaf spring mounts are bolted on. My 84 G20 the pass. side frame rail combined the side door rail and the front perch was welded in You can mix and match all day..