I have a few questions about the 3.8s becouse im new to them. I would like to swap one in my 91 s10 with a 2.8 t5. I would like to swap in a pre 87, but are there bolt patterns the bop pattern, and are they 60 or 90*? Are the 88 and ups the 60* universal? Are the 87 and earlier engines a 90*, what about the 88 and up? So could i use a 4.3 mount? Any help would be great.