My ol' man has a 306 with TRW pistons, and TFS heads. I had a extra set of AFR 185's. So I said I'd let him try them. To see if they would work any better for him than the TFS heads. Not having a pushrod length checker on hand we used the best guess stock pushrods. They worked, but I could tell the valves werent opening all the way. My brother had this setup before. My dad got the shortblock, and I got the heads. He brought us the correct pushrods(Same he used in it). The problem is now he has a PTV clearance issue. My bro said he had to shim every other rocker. Im assuming theyre stock replacement forged pistons ,and the relief isnt big enough for the 2.02's on the intake. I would just stick the stockers back in, but theres an issue with the rockers coming off. Whats the correct way to resolve this issue ? If shimming is what needs done, how do you know how much, and how do you do it ? Thanks in advance. I never had any issues like this before.