I was on fb tild about slap thrust washer. I didnt have thrustwasher on both my first topends and they lasted 18monthe between the 2. They started of quite and where they didnt have the washers it just beated the piston up. First one knocked the pins out for ring gap to lay on. Second one broke pins out again and busted squurt and junk out above the rings.  If they are not in their your running a time bomb. You coule tear it down and measure. You might be able to get by with a hone and new piston. Also rm 250 99 wrist pin bearing and billet thrust washers. Which are in forum store.