They'll all bolt up, but there are significant differences in how far inboard the A-arms mount, and the straight-6 K-members won't work with a 4, V6, or V8. The 4-cylinder K-members and the '79-86 V8 K-members mount the control arms 1/2 inch more inboard per side than the '87-93 V8 ones do. So you have to put some thought into what your goals are and what A-arms you're going to run in order to get it all to work, because some fox chassis and SN95 A-arms are longer than the rest.