Hello. I am preparing to install my KB 2.6 with 3.50 upper and stock lower. I have a 4 piece billetflow idler kit. has anyone run this combo and can share the belt length I will need? Thanks in advance.
Im looking for the same answer. I am going to be running the same set up. what size belt did you end up running? also how much boost and horsepower are you making with the 3.5 pulley?
Run a string/wire around the pullies as if it were a belt. Apply tension to tensioner. Mark string/wire, measure it, I subtract 0.5" and order that length belt. It's not hard to figure out. Just did this again for my next pulley setup. Rockauto has the best prices on belts.