As far as I know, just the light duty 3 speed (303 I think) and the T98 4-speed came standard. The clutch sizes differ. I think 10" for the 3-spd and 10 1/2" or 11" for the 4-speed, can't remember exactly. John Mummert makes/modifies bellhousings for the 223 to accept a C4 auto trans. Google his name...he has a lot of Y-block stuff!