I am just trying to see how far in the hole different stock pistons are. Some replacement pistons say .085 dish and some .115 dish. All the 250 stock replacement pistons say a 1.640 compression height but GM archives say 1.655 for stock 250 pistons. I am also going to measure and post my 1980 engine specs when I get it torn down. (As soon as I can get some time with my Grandson) Thanks again Jay 6155
