I'm doing a head/cam swap and just got the head off. Today's surprise was seeing that the valves have been hitting the Pistons. I thought I knew about my engine (it's a swap) but I'm finding its not what I was told by the seller. I am putting ported 243's on there, but have no idea what heads were on it (the casting numbers are ground off). I'm assuming they were milled. Should I fly cut the Pistons or hope it'll be fine with the new heads?

 

" Should I fly cut the Pistons or hope it'll be fine with the new heads?"

A "novel idea"......Check the clearance, and act accordingly.

 

Run it and cross your fingers.