i need a used engine so that i can rebuild it. im taking a class at school and i have a 525i which is far from sporty, so im plannin on taking another m50 and overboring porting polishing etc etc, OR tryin to fit and s50. will an s50 mate with my 525i auto tranny? or will i have to get an m5 tranny too. either way i can do anything, we have such a rad shop. any of idea will be MUCH appreciated. i dont care if i make some engine then break it either cause ill have my engine im usin right now to put back in. thanks guys. -justin