I don't have a serpentine belt, but this is what I think - you'd need a shorter belt
Long answer is: Swapping your stock pulleys for smaller ones will add more slack than the tensioner pulley is able to do it's job with. Now, how much shorter would the belt need to be? Not a clue... ask the company you're planning on buying the pulleys from
To answer your original question - yes you do need a different length belt.
However, I would strongly recommend NOT putting these on your truck. I installed them twak ) and they caused way more trouble than they are worth!!
They would work great if you are only driving a 1/4 mile at a time, but for daily use on a truck, they suck!
If you are determined in using them, I will gladly send you the HyperTech Power Pullies that were installed on my Bronco.
Replacing centering joint ball in rear drive shaft. I have this gold ring that looks like a seal that goes on top. But what I had on is longer in the sides more like a cap, it does have a rubber seal.
The gold ring could fit in the cap, but the cap would not sit fully in the centering ball. So...
As many of you already know my Son and I are new Bronco owners. We are excited to learn and do as much as we can ourselves with our new Bronco. I wanted to take it to a mechanic that is good family friend of ours to have it initially looked over. Our newly acquired Bronco had been parked in a...
Purchased Spicer 2-94-28x u-joint u-bolts for the 1330 u-joint on the front driveshaft, transfer case side. Bolt diameter is good but they aren’t long enough. I can barely get the nuts started with the lock washers on there, and tightening them up only pulls in about half the nut threads...