Better than the Jeremy Kyle show Chris, well done. Hope you don't mind me putting the reply from Frank Quintero at Vortech USA below so that we can see from the horses mouth what they say about the the 3.12 pulley and the correct belt that fits the pulley, actually it shows that we were going down the right road in the first place but I do like the American disclaimer at the end, LOL. This is not a hijack of this great thread but I thought most of the group would be following the pathfinders adventure with interest.
Hello,
Typically if you only drop one size down on the pulley you can reuse the same belt. The belt does not need to be really tight. A .25†deflection on the long side (side without tension) is tight enough. If the belt is to loose try a 79.25†or 79†long belt. We have not verified what belt works with that pulley in-house.
Thank you,
Sales
AirPower® Group
Engineered Air Management Solutions
Vortech / Paxton / Vortech Racing / Vortech Marine / Vortron
1650 Pacific Avenue
Channel Islands, CA 93033
Main: 805.247.0226 ext. 244
Fax: 805.247.0669