The bellhousing wont mate up to the 51 crossmember. A 1948-1953 bellhousing will need to be sourced. 1954 and later bellhousings have "angled mounts". 1953 and earlier bellhousings use a different rear motor mount. The bellhousings will interchange from chevy to gmc, but will not interchange into the chassis from 1956 to 1951.
Next problem to solve would be the 6 volt/12 volt problem.
After that it is just the long motor envy.
There are plenty of chevy 6 powered gmc trucks out there. I personally would never buy one as it seems even more sacreligious than dropping in a sbc motor. Sure it could be done. The question is "Should it be done?"
