OK. I can see I crossed a line with the SBC comment. LOL. So, please disregard. We might be on the lookout for a 400 pontiac motor. The good news is we put a new head gasket on the cammer and it seems to have done the trick. Compression between 160 to 170 on all cylinders. Intake manifold has a leak now so will have to reinstall, but I think the rest of the motor survived the spark plug melt down...Time will tell..Appreciate the comments and I'm glad to find out that a 400 motor might not be too hard to find after all...