Race Engine hours

[txhokie4life]

So when one talks about the # of hours between rebuilds on a race engine

what is the cause of the need for rebuilding?

Is it valve guides? rings? ovality? bearings and oil pressure?

I'm trying to determine whether I stick with a 3.8 build or back down to a 3.6.

I've been told the 3.6 will likely last a lot longer, but a lot of the components I have are setup for a 3.8 and while they may need reconditioning -- its a lot cheaper than buying P&C's and new head work to mate to 3.6's.

thanks,

Mike