[bigblockv6]

My mistake, you're right the 432 did not use the smaller bell housing that the 379 used. As far as the 5500 series using a 401 what production years are you referring to? I know for a fact that the only gas V6 engines available on 5500 series trucks from 1967-72 were the 305C and 351C, of course that may be diiferent for 1965 and prior years of the BW,LW 5500 series trucks.