This is MY 67 Camaro

[Build-It-Break-it]

I think you should try and bolt everything up to the subframe and check everything else before you dig any deeper. Check frame rails for square and level ,steering linkage clearance, radiator support location and mounting, etc etc.

I think pushing that upper shock mount inward would cause more problems. Your basically going to have to rebuild/reconfigure the control arm mount/shock mount to be safe and still retain correct geometry.