I have some questions about interchanging parts between diff year 300s I have a early 85 in my F350 that is really tired had the pan down the other day to roll bearings in it and the crank was pretty worn, not to mention the first owner overheated it real bad one time so I am kind of suspect of how good the block is,,,Only good thing on it really is the new head the first guy had put on it right before I bought it from him,,,,I have a 91 300 my brother got me the other day that seems pretty tight came out of a van I think ,,,,My question is can I just rebuild the 91 300 short block and put my head on it for a fast swap into my 85 F350 and when I do this will it use the same rings, rod and mains, oil pump, cam bearings, and gasket kit as the old early 85 300??? I kind of have to do this over a weekend so I can have the truck for monday and I figgure one of you guys will know what swaps and what won't

 

I would use the whole engine. If you put your head on the 91 the compression will be down the 91 used the 6x cc head the 85 has the 76 cc head. The 91 used a lot deeper disk in the piston then the 85 uses deep dish larger conbustion chamber = lower compression.