Being a newbie to the LSR world but having a 20+ year drag racing background I am a bit confused when it it comes to engines run in LSR. In some posts ive read and in talking to Sparky, drag racing motors arent used much in LSR. Lets just say for kicks and giggles I want to build a NA 555 cid BBC to run in an AA class. The basics being Dart Big M block, Callies Crank, Oliver rods, JE Pistons, Comp Cam roller, 904 lifters, Jesel rockers and belt drive, Dart Big Chief heads, manifld, 1050 domintor etc. Pretty much your run of the mill super class engine. What would be different about an LSR engine parts wise over the stuff that I have listed? Now granted I havent gathered anything up yet, nor do I have ring thicknesses, valve or valve spring types listed. I understand that an LSR engine has to last much longer than a drag motor but the confusion I have is parts are pretty much parts. How do the two engines differ when yet they pretty much use the same internals.