I will say this:
Many times folks build an engine but trust others for setting everything up. When this happens, the guy tuning/setting it up BETTER know what he's doing. Nothing against your guy, I don't know him. I'm just speaking in general. Usually, the biggest disappointments in power output come from these type of builds. I not only recommend, I insist that a person knows how to do basic tuning, carb settings, timing - initial, total, curve and just general understanding of it all. As these cars get older, and the good ole' boys keep leaving us (RIP), there just isn't enough guys out there to get these right. Again, nothing against your tuner at all. He may be great.