Record the measurements that you get in the area you are wanting to cut. Walk your piston in between the indicator and the punch. Make sure every thing is solid and repeats '0' when cycled. Or you could take it to a shop that is has pleanty of knowledge in the Rat or splay valve engine build area. Position the indicator so that the tip touches the tip of the punch. Am I correct in saying that since the big cam with a lot of overlap cleared - Then a smaller cam with less duration and less overlap will automatically clear I think it would. Push downward using steady pressure and watch the gap between the drill chuck and the valve seal decrease until the chuck contacts the seal. A Performer cam may also be put in place of the stock cam when I change the heads. Pull the valve up slightly off the piston and start the drill. I currently have a Performer 289 intake and Edelbrock 1405 carb. If number is negative there is an optional step of pounding head against punch mounted in vise. So, after fly cutting, the Pistons have 0.080' and 0.100' clearance. I don't mind hardened pushrods, but I don't want to have my pistons flycut (unless that can be done with the pistons in the block, which I doubt somehow) 4. You have to take the engine out, remove a heap of tinware (the cooling shrouds etc), the inlet manifold, the heads themselves, the cylinders, the pistons. Subtract the amount that you need to remove to make you happy and this will be the resulting end thickness. 2) Use a center punch with a good OD finish (available for cheap at most production tool stores, like J&L Industrial) through the guide and put dimple marks in the valve pockets. Record the measurements that you get in the area you are wanting to cut. 1) Put the pistons in the bore at TDC (each one) with enough masking tape on the ring land area to keep the piston centered in the bore. Make sure every thing is solid and repeats '0' when cycled. Position the indicator so that the tip touches the tip of the punch. You will need a piston 'dome checker' or a the shade tree equivilant of a bench vise, long punch, and magnetic base mounted long travel dial indicator. These pistons can make a great foundation for a reliable engine! Just don't expect to fill'er up with 93 Octain and be happy! If the tech line can't help it is real easy to measure the thickness of the piston. The time to do this is when they are out of the engine.

Call Speed-Pro and tell them what you are wanting to do and they can help. Opinions expressed are solely my own and do not express the views or opinions of my employer. No.No.! The point is to know match your components and get your combination outlined before you start. Do the work yourself is the only way to get things done right.

Flycut pistons yourself