Project Greyscale 1971 Trans Am

[preston]

forget about the body.

Setup reference points where the rear LCA's mount, build some bolt in brackets with measure points if you have to. Worry only about the front LCA mounting points measuring correctly to the rear LCA mounts, both straight line and x-measurements. Obviously get your mounting height where you want it on the subframe first.

Maybe I'm not understanding your issue but it sounds like you are trying to align the subframe both with the rear frame and the body. Neither of those matter, you need it straight with the rear suspension mounting points. If after you do that you find the wheels not centered side to side of front to back in the wheel openeings you may need to modify the body openings or something else. But dont' let the original frame or body affect how you measure and bolt up the suspension mounting points. Get that correct and then worry about how it fits the body later. Move the sheetmetal if you have ot.