Re: 4.0 pistons
Okay, Maybe my years are showing, but adding intense mods to a stock 4.0 is dangerous to it's health. I realize straight 6's have been around for eternity and are strong, I remember watching Chevy 6's running against Ford flatheads and winning, but most of those engines were rebuilt for the purpose, not taken off the street.
What I DO know is superchargers and nitrous tend to melt cast pistons and other nasty stuff, so precautions should be taken. I laud anyone who wants to hot-rod a 4.0, but they take responsibility for major problems.
JMHO, however. Trying to get more horsepower out of your engine is bred into the American spirit and will never end. When I was young, I did all that stuff, drag racing, road racing, boat racing, motorcycles, you name it. I'd be willing to help anyone who wants to build a hot engine, but personally, I'm looking for reliable transportation in my later years. Off-roading sets totally different parameters on an engine.