I think there are several issues here...I'll try my best. If you are concerned that the bigger dampener will place the pulley farther out from the front of the block...I don't think it will. I swapped out a 307 with a miniscule dampener for a 350 with a huge one and all of my belts lined up fine. (I used the pulleys off the 307)
If you swap dampeners from one motor to the other, you need to concern yourself with the location of the timing mark...somehere along the line Chevy decided it would be a good idea to change the location. Of course, if you try to put the big dampener on the 327, it probably won't work because the timing tab on the cover will be in the way.
Another issue to think about is the fact that the early dampeners were press fit only, and the later ones are held on with a bolt.
I'm almost certain that any balancer from an internally balanced will work on another int balanced engine. (SBC-wise)