Ok, I've searched and read 'till I'm about to go blind, but I have a few questions on Ls/Vtec. I know that for max reliablilty the bottom end should be upgraded a little (rods, pistons, etc). But suppose the LS rev limit was observed (~7000), after all the B18C1 hits max power at 7600 so you'd be losing "only" 600rpm and the associated HP. Would the LS bottom end retain it's reliability and run "worry free" if that 7000rpm limit was adhered to?

 

Yes it would be more reliable but it wouldnt be a very potent setup. Vtec motors rev high because thats where the power is. so that loss of 600-1000 extra rpms would mean a low hp motor.

Just have an experienced person build the ls/vtec on stock rods. A good builder can give the motor a pretty long lifespan. In the meantime build another block with built internals.