I have a 350 Buick engine that was rebuilt some time ago. Now in a project vehicle of mine. It is a 73 or 74 block. I have the original heads that were machined, but never installed since they had surface rust on them. Found a set at the local machine shop that were cheaper than cleaning these up so I just stored the original heads. Now, I want to do a little porting and install bigger valves. How can I tell how much the machine shop shaved from the original heads when they worked them? The heads were done when I bought them, so I don't know their history. I do have a 68 model 350 that has never been apart. Should I just work those heads so I know exactly what has been done to them or will they fit my later block? I have used 67 430 heads on a 455 engine, but don't know about doing it with a small block.
John, the 350 is the same as the 455 in this respect, earlier heads can be used on a later block, but later heads,73 and up, have 2 extra water passages per head that need to be plugged for use on a 72 or earlier block. The thing that makes it slightly more difficult is that the holes that need to be plugged are oval shaped, not round(as is the case with the 455 heads) so you first have to make the holes round before you plug them. Jim Burek P.A.E. ENTERPRISES
I was think about this thread, it was either here or thirdgen.org that someone had a similar problem and need to plug off some holes. [But i think they went into the combustioin chamber] They backed them with model clay and filled them with aluminum from some old pistons. I Don't know but I would say grinding in a few locking groves would be in order. Might save a few buck.
