If you cut coils for that much drop, you need to move the lower ball joints inward. Back in the early 80s, before drop spindles, on my 81 C10, I had a local shop make me a set of coils that gave a 4” drop. I cut out a square around my ball joint, removed 5/8” more behind the piece, then slide ball joint piece back in and welded it. (Depends on your welding skills) On top of the cross member, where the upper control arm bumper hit, I added a 2” spacer to limit downward movement to keep the springs in the pockets. I removed the frame extension brackets and mounted the sway bar bushings straight to the frame. When I had it aligned, all they had to adjust was toe in (I had gotten it close)
Took a torch to some flat bar and bent up saddles for a rear flip kit. Offset drilled the holes about 1-1/2” to move the rear back to center in wheel wells. Ground down the front of the saddle to get driveline angles right. Went thru the parts store catalog to get shocks that were shorter.
That truck still has the same setup, as I saw it still running a little over a year ago and looked at it. Talked to the current owner several hours after I told him what and where a buddy stamped something into the frame. When I stated what was there, he realized I had built the truck.
Sad thing was, when I got rid of the truck, it was running a stout bbc, but currently has a small block.
Again, it all depends on your fabrication skills, as it can be done, and made to work. Back then, we built them, not bought them. You couldn’t just go buy parts and change them as they did not exist until a few years later when the craze really caught on.
Sorry for the ramble, and keep us updated on the project
