I have a 2001 F-150 reg cab 4.6 5spd xlt, I bought an intake kit which has ignited my interest in making this truck go faster! I am about to purchase gibson shorty headers, a super truck exhaust from gibson, and a 75mm throttle body fromm bbk. I have had vehicles in the past with headers and high performance exhausts, so I'm pretty sure about these. I just don't know what to think about the throttle bodies...Are they worth it? Please someone with experience respond. Also would like to know if anyone knows of some decent shorty headers that won't short change me...450.00, man times have changed! One more thing are the spacers junk? Are they just high priced wistles or what. I like to read peoples experiences, please share.
I'm new to the site, sorry about the babbling on, great to be here.

 

Count one vote that the spacers are pretty much just a noise maker. I didn't see any significant improvement. Possibly a small boost to the mileage. < 1 MPG

Greg

 

Skip the throtle body and get the manifolds extrude honed. Opinions on the shorties are they are not worth the trouble or the price and the quality is not that good. Longtubes are way out of hand price wise. Larger throtle body will do very little for you unless you are blown.