[DirtKing]

your pistons probably have some sort of reliefs, but I'm almost certain you'll be notching them if you want to put any sort of cam in your motor...and with those heads it would be a waste if you don't! #1 those heads are milled so they sit closer to the block deck. You just lost valve to piston clearance! #2 canfield probably uses different valve centerlines than the stock heads. I know they use bigger valves. This means even with stock valve reliefs, the reliefs may not be where you need then to be. I get them notched and do the job right. You'll never regret it. (like you would if you ran into valve float and put valves through your pistons)