BBK 15550 3-Piece Underdrive 8-Rib Aluminum Pulley Kit

i just finished installing my new pulley set and throttle body spacer and i can see a big difference in how the engine revs it comes up very fast and it revs higher than before by about 1000 rpm .but i do not feel a major difference in the power i am sure its more but not a big difference

the pullies gave me a noticable gain at the 3500 to 4500rpm range in my 03 ford f 150 the only thing i didnt like was the directions didnt say that i would need a smaller belt the result was alot of squeeling but i got a smaller one on now and it works awesome

Installation was going pretty well. Instructions were nice but when I went to install the crankshaft bolt it would not thread. Found out the bolt was incorrect. Not a good thing when your only vehicle is tore apart. Went all over town trying to find one but none to be found. I guess the 12mm x 90mm x 1.5 is not very common. Nice thing is I called BBK and they sent me another, no questions asked.

Great performance gain plus an extra mpg, but kit had wrong crank shaft bolt which wedged itself into crank itself so pulley can't come off no matter what (that means no supercharger like I planned). If you get this check to make sure that the bolt you get has a tapered end, and is not threaded all the way. If it is threaded to the end then you are asking for trouble!

The BBK pulley set is one of the best upgrades i've installed on my truck. Engine runs a little bit smoother and you can feel the increase in power especially when passing on the freeway. I haven't had any trouble with the electrical systems while at idle but this could be because i have the optional 130 amp alternator. MPG also improved slightly.

The BBK pulley system is a must have for any one looking for some horsepower. Very noticeable increase in power.

Noticable power increase and better fuel mileage.