Not a big fan of nitrous myself but know a lot of people like that instantaneous boost in HP it provides. It is my observation that most people who use nitrous are hard on their cars in general. I've heard more than a few transmission and rear explosions (or real bad rod knocks!) just after catching a whiff of the gas.

Anything other than a 50-75HP occasional squirt demands a well engineered total rebuild. As mentioned, steel crank ($750-$1,000) and extra strength rods ($300-4500) are the minimum. High quality, low compression pistons are better. Nitrous is is approximately 50-percent richer in oxygen than air and as it squirts into the combustion chamber a whole lot of oxygen goes with it. That additional oxygen requires additional fuel or you will end up with a cutting torch effect and melt the pistons. Allow $750 as a minimum for pistons. And the list goes on...

Glenn