86? I believe u have 2.8 GM v6 engine correct? Idk about that one, never experienced with 2.8 GM you should go and start thread in modification and repair tech so much eyes ball out there i sure there tons of guys with experienced with 2.8 GM engine. By the way on 4.0 no u don't need to remove or anything with transmission for rear main seal. and there is tons of write-up on how-to: replace the rear main seal.