Possibly I dont know much abouy the gasser transfercase. You should have a NP241 t-case in the diesel check what case is in the gasser? Do the cases look the same? Also I know as far as the NV4500 5spd trannys in the diesels were HD and the gassers were a lighter duty NV4500 but looked the same, maybe the same as far as transfercases.
-Jordan-