The answer is, Yes, with reservations and/or modifications. It will depend on the years of the parts involved. The bell housing bolt pattern is the same. All the 727's that came behind a poly are the one-pin neutral safety type so if you need back-up lights, you'll have to figure something else out to operate them. The '64 and older 727's use the ball and trunion U-joints which are not a desireable setup. The '65 and older 727's are all cable shift which is also not the best, and without major mods, can't be used with the later linkage type shifters. As for the crank register, the only small block engine it won't bolt to would be the '64-7 273 with the stock crank.