As I understand it, they both can use the same input bearing, either a 307 or a 308 depending on the main case, so I would assume the diameter is the same. My question would be "why do you ask" the bearing retainer can be of a different diameter where it fits into the bell housing. There are at least 3 different ones that I know of. John Althaus 64 Savoy Hemi 4spd Lewisville, TX 75077 214-673-7540 cell In a message dated 2/21/2009 10:43:04 A.M. Central Standard Time, neal.zimmerman@xxxxxxxxx writes: does any body know if a regular B-body 4 speed has the same diameter input shaft as the hemi B-body 4 speed. I know the sp lines are different , but i am wondering about the actual shaft diameter. neal zimmerman, eugene oregon **************You can't always choose whom you love, but you can choose how to find them. Start with AOL Personals. (http://personals.aol.com/?ncid=emlcntuslove00000002) [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.