hi i am new to your forums but not so to car repair. it has been awhile since i worked on a chev so i am kind of rusty my father bought a 91 Silverado the other day and it has a 350 engine and a 5 spd manual with 4 wheel drive. but it also has two blown head gaskets it was also missing a few parts because someone tried to fix it before. i fixed the top end and now i am working on the bottom end the pan was unbolted as well as the oil pump and all that stuff underneath i think most of the bolts are there as soon as i can get the pan out i can jack the engine up and almost get it out but not quite. what size is the oil pump bolt. i was told not to worry about the bearings they didn't make noise when they ran it for a few minutes.