How common is it for an LT1s to spin bearing?

 

Really depends on mods, and how they are driven. I personally know several people that have done it, including myself. Once you start camming them and spinning them 6500+, and making power up there, it gets more and more common. On a stock engine, i rarely have heard about it happening unless it is just being abused.

 

We are talking an engine with less than 60K miles with a LT4 conversion kit?

 

anything stock is naturally JUNK! if your gonna be makin power with stock stuff still in the car then be prepard for the worst! stock bearings are JUNK and wont hold once you start drag racing to 7k and running really fast at the track. especially a stock motor with high miles