I can get a set of heads (462) 2.02/1.6, cheaper than redoing mine. But Each head is a different year, he also said there's a 4cc difference between the heads. Is there any drawbacks to having a 4cc difference?
I would not run it this way, too much of a compression difference from one side to the other, more than 1/2 point.
Good news is it's an easy fix , just grind the chambers of the smaller head to basically match the larger(get within 1 cc) if it is a chamber shape difference. If the chambers are the currently the same shape, then it is likely that you can mill the larger chambered head .025-.030" to drop the chamber volume down to the smaller head size.
One way or the other you should be able to make them match. A good examination should tell you what you are looking at.