So my setup has the 10% OD and as of right now 3.3” pulley, with 10mm spacer (pictured) to try to fight off heat soak a bit-
the stock K061098 belt and 8 rib rpm belt (previously mentioned) are definitely too short.
Just posting these numbers because they’re not posted on Gates’ website/length lists and available through rockauto/oreilly since evidently napa stopped carrying these non standard sizes.
i’m getting the tensioner percentage use (zero being no tension applied, 100 being fully exercised) from some mustang forums where guys were/are running green and rpm belts and tryin to figure all that out, fwiw
RPM (30% tensioner, not stretchy)
K081092RPM
K081102RPM
K081110RPM
K081145RPM
HD Green (70% tensioner, stretchy)
K081092HD
K081099HD
K081102HD
K081124HD
K081131HD