96 Cobra + KB 2.1 = 400 rwhp?

No.

My wife's dyno'd at 337 on a dynojet before they shut it down due to a lean condition. After the lean situation was corrected, it dyno'd 338 on a Mustang dyno. My understanding is that a mustang runs about 10% lower than a dynojet, so that would put it 375-385 on the dynojet. That said, the KB puts out gobs of low end torque and turns the Cobra into a completely different car. I'd highly recommend it for the fun factor alone.

Eventually, I plan to upgrade to 42 lb injectors, a Lightning MAF and a custom tune. That ought to put the car well over 400 rwhp, but out of the box, KB's claims are greatly exaggerated.

No. The kit does not come with larger injectors. It is set up for a stock engine and accessories unless you tell them otherwise. When you order your kit, you have to fill out a very extensive questionaire detailing all of your mods. The lean condition turned out to be a fuel filter that had some crap in it, even though it was less than 5000 miles old. "Tuned perfectly" is way off base. "Safely tuned" is what it is. They supply you with a custom burned chip, based on your questionaire, that will replace your Jet chip.

The car has an SLP cat-back and a stock H-pipe, along with a fenderwell cold air intake. The KB completely replaces the intake manifold on your engine, so there is nothing to do there. My wife's car has Eibach springs and 3.73's like yours, so the only difference will be your off-road pipe. Maybe 10 hp max.

Yeah, KB aren't good for over 380-390RWHP. If you do go with it....save your lower intake.....those things are EXPENSIVE at the dealer and even on EBAY....rediculously expensive.