Is it possible to over port a set of LT1 heads on a 350ci? What would be the drawback to too much or is that even an issue? I have heard that too much is not good.

 

There is such a thing as a bad port job, but "too much" on an LT1 head means going through the wall, which can and does happen, so the answer is kind of "no," if the LT1 heads were capable of 400cfm then maybe it would be ridiculous for a 210/220 cam user, but there is no way really to get there on an LT1 head.