Input Shaft Spigot Bearing Woes

[wherzmespana]

I have now had 3 failures of the spigot bearing that sits in the end of the crankshaft to receive the input shaft spigot. I am running an LS1 with a G50 gearbox. The car is 99% track use so spends next to no time sitting in neutral or slipping the clutch but the bearing only seems to last for 500 miles or so? Help.....................