Hy uglydukwling, welcome, yes there are adapters on some of the larger flywheel/clutch/transmission applications. Does the truck employ a flat mount at the rear of the bellhousing, or is it an angled mount? I don't think I've ever seen a flat mount adapter/bellhousing setup. If you were to use such an adapter/bellhousing that would mean re-locating the engine front mount forward of its present location due to the increased width of the adapter/bellhousing setup. Have you considered swapping to a different transmission, or are there p.t.o.s involved? Hope that helps.
