Just used my last engine from this kit. I built a Pontiac GTO and swapped the 400 for the 421. I love these kits and have purchased several for the 421 alone and having a small block Chevy engine ready to go is a big bonus. The parts go together without issue - the only problem I have is the chrome ( I know that doesn't sound right but the chrome can be removed) I added full details to the engine.
I would recommend this kit to all builders.