I am new to IT racing after many years in small bore prod and GT. I have had 1 person tell me that these engines are good for 40 to 50 hours with general head maintenance. I have a Datsun 1.4L with 28 hours on it (it is reasonably stock per the regs). I would like to get some "expert" advice on where the rebuild threshold really is.

Thank you so much for your help. Really enjoying what appears to be a minimum maintenance - high enjoyment car>