Try here for information: http://www.streetandperformanceelectronics.com/lead.htm

I've installed one of theirs on a 4.6 F150 and it seemed to work as promised. The owner was happy, anyway.

Tin Kicker

VFAST, we got no official timing, but the thing was definately more responsive on takeoff. Like I said, it was a 4.6. It's major problem was too little motor for too much truck (big mudder tires, 4x4 extended cab, loaded--heavily loaded). It really felt stronger, though you know how that goes...might have been a good tailwind in that whale.

The whole premise behind items like the Power Tower is more bottom-end due to the more focused stream of air. Like a taller manifold on a carbed car making more bottom end than a short one.

MDVALDOSTA, no, I don't believe the 20 hp claim given for the Vortec on each and every box they sell. That was probably along with a K&N, some 104 octane boost, AND a tailwind. The thing with bolt-ons is they could advertise to a guy he was making 20 more hp when he was only making 1-2, and he would wholeheartedly believe it as long as he could feel a little pucker in the cornholeo everytime he stabbed the pedal.

Bottom line is, the owner was happy, I was paid, and the air continued to twist down through the might Power Tower. Long live the dream.

It's a good add-on and worth the money if it FEELS like it's helping.

Tin Kicker

Never seen the Napa piece...interesting. Gotta' check their stuff out more.

Yeah, I had it totally backwards on the intake height/torque ratio. My mistake for the day, I guess. More height equals more hp, less height equals more torque, everything else being equal.

I agree with VFAST about where to spend the $100...I'm still a recovering carburetor user of many years, so a lot of times I don't even think of the FI pieces you can bump up. VFAST, your .02¢ was really worth .25¢...good idea.