Just had 383 stroker installed and car was running good - took it to the dyno and all was fine, oil pressure was good - brought car in to have and oil change before putting it away for the winter and found front crank seal leaking. Checked crankshaft end play and it was .018" - the machine shop that built the motor set it up at .005" - Removed oil pan and found front of thrust bearing is wiped out but the back is fine - crankshaft is being pushed backwards or walking backwards but can't figure out why. Any suggestions please.