I gotta ask why you would want to run nitrous on an Explorer. You don't want to use it below ~3000 rpm or in traction limited situations, or for prolonged periods of time. It really is useless during offroading as far as I can figure. Now, if you want to surprise some punk kid in a Beretta at a stoplight, N2O is for you Dead Link Removed
I'm not sure of the fuel capacity of the stock pump on a 4.0, and I'm pretty sure they use hyper pistons, not stronger forged. With that in mind you wouldn't want to run much more than a 75 or 100 shot at most.
I've been using n2o on my drag cars for years, and have installed kits on quite a few cars over the years. Feel free to email me if you have any more questions.
And as far as NOS being the "experts," well that's only as true as the guys at NOS would have you believe...
Later, EB Rally
------------------
From my favorite Harley T-shirt: "If you can read this, my ***** fell off."
