I bought a 68 firebird 400 that has a 71 gto engine in it that seems to have serious problems. The car was fetched out of a field after being parked for years.
The engine idles okay while belching lots of exhaust. When it's rev'd up in park, it vibrates really badly. I'm thinking that it may have a bent connecting rod or similar issue. I guess I have to get the engine out and apart to see; something to discuss with my mechanic friend.
Since the engine is not the "matching numbers" item for the car anyway, I'm thinking it really doesn't matter what engine goes back in.
Someone mentioned earlier that the 350/400 etc are all the same basic block. Would it make sense to just buy a new GM crate engine for the car or would it be better or cheaper to find a machine shop that can rebuild what is there already? Would the various GM crate engines such as the ZZ4 HO drop right in?
My goal is to restore the car to similar to stock appearance and performance. The rear won't be tubbed or anything like that, so there is a limit to how much HP this car can plant anyway.