ORIGINAL: Boozshey

Well everyone will reccomend a Whipple or Kenne Bell SC, and 3.73 gears not 3.90's. Also I am assuming the 3.90's aren't FRPP. You might want to go ahead and rethink that if it's the case and get the FRPP 3.73's.

If I were you I would go with the Whipple, only because I love the WHINE of a SC.

ORIGINAL: CataclysmGT

After doing a lot of research and asking around, I've pretty much decided on the Whipple HO (closely tied with Ford.....which is a good thing) or the Kenne Bell 2.6L
Hard to say exactly which is better, as the Whipple puts out more peak boost, and slightly more power then the KB, but that may be a problem with stock internals. Whipple takes pride in their "tune" and says its the most advanced in the industry, which may save problems down the road, but KB doesnt seem to cheap out either on R&D. Either one will be awesome, and give you tons of torque, which is what you want for a street car. Imagine cruising on the highway, just over 2000 RPM, and flooring the gas with 400 lb-ft of torque right NOW......thats passing power....and pretty amazing. The torque an SC makes means you wouldnt even have to redline if you didnt want to, short shift at 4500-5500 RPM, save wear and stress on your engine, yet still accelerate at the same rate!. I guess if I blow an engine doing my normal driving (I dont race, so the stress my engine would recieve will be low on average) it give me an excuse to buy the new Ford Racing forged bottom end (including block) for $4500......hahaha.
Biggest thing to watch is the A/F ratio.....buy and Autometer gauge set or something (looks kickass.....search for Whipple mustang on youtube.....) and keep an eye on it......any more then 12.5 full throttle...probably time to back off for a sec.

Soon, I will join the 400+ RWHP club........and all will be well in the world!.