The Stovebolt Site Forums The Shop Area Engine Shop Hopping up the GMC 270 in the firetruck?

I picked up two 1958-59 270s. The one from a 1/2 ton has vacuum advance and the one from a 2 ton does not. I've been told the large truck usually did not have vacuum advance.

So I wonder if a dizzy from a Chevy six can be used in place of the GMC non vacuum unit, or if parts from a Chevy vacuum dizzy can be used on a GMC non vac. unit.