Thanks John and Pat for the advice and input! Before I pulled the heads I stuck a Q-tip with blue on it through the spark plug hole and applied it to the valve by spinning the valve with my fingers. Then I pushed the valve into the piston and spun it. When I pulled the head it left a half moon almost dead centered in the valve relief. I talked to a machinst that has a jig and fly cutter set up to make the process fairly cheap and all pistons will be the same. I was bummed thinking about tearing down the motor at first, but its been a fun project and the truck still runs strong with the Small Block in it, so I decided to take all the time neccessary to make the Big Bock right. I think I will also open up my ring gaps a little (installed speed pro moly rings with the top rings at .018) thinking about going .020 to .022 to be safe with the NOS. What do you guys think? This motor should make max HP around 5500 to 5750 don't think I should ever need to turn over 6000. Should I shoot for .080 intake clearance for a cam with .600 or so lift (a little room to grow in the future). One last thing that has bugged me is bearing clearances. I ended up with .0025 on my rods (just right) and a little over .003 (.0032 to .0034) on my mains. Do you think that is to loose on the mains? my machinist says no but what I've read says run big blocks on the tight side. I am running a Melling high volume pump and a Moroso pan with trap door and screen. Last question! Rod side clearance was .014 between a couple pairs, is this to tight? Thanks again guys for your help!