j3rry

ok i tore my motor apart cause was gonna replace all the gaskets . and wanted to see why i kept fouling num 2 plug . well when got heads off valves looked good other then num 2 cylinder those valves on that head were darker then hell n caked with oil .. my buddies dad said my rings are shot but idk if would be the rings or jus maybe valve seat ? every piston i can bring it up to top dead and i can move them back in forth a lil but not hole lot . is that normal should i be able to move them side to side ? n also car never did smoke jus some blackish grey every now n then but figured thats cuz was runnin rich ? and if i gave the car hell the check engine light would come on and would idle bout 1100 rpm's

87Stallion

Sounds like its time for a rebuild. If it were mine Id send the block to a machine shop and have them check it out and then Id rebuild it.

67mustang302

You'd need to do a leakdown test to be sure, but the heads have to be on for that. And the pistons will rock around a bit, the top of the pistons are a fair bit smaller than the bore since they expand quite a bit when they get hot.