From John Kennedy's site-
"It has come to my attention that there are other suppliers representing OE fan clutches as 180° or similar reduced spec claims. Just because someone says it calibrated differently does not mean that it is. Certain "Severe Duty" units offered are merely OE production units. The OE clutch, as well as mine are built by Borg Warner, and are physically identical. The difference is in the calibration. This is not a modification, rather a variance in the calibration when built. The Kennedy Diesel fan clutch is a unique part number, that is built in special batch runs. There is a lot of expense involved with a special part number, and I am required to pay in advance for parts that I will not see for 6-8 weeks, and purchase minimum quantities. This is a serious investment that I will continue to make so long as demand continues, but BEWARE imposters!" - JK
Make sure you trust your vendor!! You've got to wonder how SSdiesel can sell a "calibrated clutch" for $100 less than a known, tried and true vendor. Are they just selling the Hayden clutch? I don't know the answers, but if you want 100% assurance that you are getting a "calibrated" clutch buy from Kennedy. His products have been tested and reported on by a lot of members here. Not telling you what to do... just sayin' is all.
1996 GMC K3500 Crew Cab Dually 8ft bed
Rebuilt engine 2/10 18:1 pistons, forged crank, Fluidamper, dsg gear drive timing, high flow oil pump, rebuilt GM8, turbomaster, Kennedy ECM, 4" exhaust, wrapped cross-over and down pipe, '98+ cooling, Duramax fan, aftermarket oil cooler and hoses
Rebuilt tranny 2/10