The engine in my 85 Blazer is dead so its time for a new one. I have a friend of mine with a 350 that is almost new he bought it for a project that never happened and its just collecting dust in his shop. I ran the casting numbers and it says 69-80 350 2 or 4 bolt main I already know its a 4. While I was checkn it out I noticed that the way the starter motor bolts up is different I think but I'm not sure If anyone can tell me whats different about it if anything that would be great. P.S. He bought the engine new in 78 he thinks if that helps at all