Stock 1/4 mile run times...

[xxxBlakexxx]

99+ are all PI. PI means "Power Induced" I believe. Read the latest MM&FF for a great explanation of the difference between '98's and the '99 motor as well as other years.

Many of the mod (for TB's, plenums etc...) manufacturers when they quote HP, they actually mean rwhp, but they are ALWAYS very optimistic. Also, the amount of gains depends on the type of motor and other mods. For a blown 4.6, sure, just adding a 75 mm TB might get you 10 or even 15 hp over the stock TB. The key is not how much hp a mod adds, but how it works with your other mods AND the mods that you plan for the future.

Increasing your TB to a 70 mm or a 75 mm is a great idea for a place to start especially if you plan future mods. Same goes for a plenum. The bigger pay-offs will be down the road. This is why some of us jumped on you a little for waisting time with a spacer.

If you plan on making big changes to your car over the years, then do things right from the start and follow a logical path. The reason why there is so much used crap on ebay is because so many guys don't take this advice.