[bigblockv6]

I went from an 11 to 12 inch clutch on my 68 KM-2500. The particular setup was designed to be a replacement upgrade that fit all 1/2 to 1 ton GM truck applications and was compatible with later model 12 inch clutches used in newer light duty trucks. The only problem was the disc wouldn't fit to the V6 flywheel so the parts store sent it back to their distributor, it came back the next day with the center hub reversed. All I can figure is it was taken to a local clutch remanufacturer in San Francisco that did the modification.