later 904 mount to a 65 block

Yes, a 68 transmission would work fine with a later motor. In fact the shifter and lockdown linkage should bolt up as well.
i didnt really make my self clear sorry about that but what i was asking is i have a transmission from a 68 dart i know 1968 was when the changed the diameter size on the back cranks but if the 68 dart had came out in 67 as the new year model would it have a 67 model transmission with the small diameter snout on it? Or would it have been changed already? Thanks For The Reply really helpful