Misses around 4,000 rpm when WOT and bogs down/stops pulling

My 95 GT 5.0 was missing around 2,000 rpm and running horribly. It only has some minor bolt ons. I took it to my mechanic and he rebuilt the distributor. He said it needed a stator assembly. He set the timing back to the factory 10 degrees. Car now runs fine under normal driving, but at WOT it pulls until 4,000 rpm and then misses and stops pulling. I spoke with my mechanic and he is saying to try a new distributor, but I just paid over $300 with parts/labor having him rebuild my current one. Any suggestions before dropping more money on a new distributor? I have already changed the plugs, wire, cap, rotor and cleaned the MAF before taking it to the mechanic. Could changing the timing back to the 12-14 where it before the distributor rebuild possibly fix it?

Thanks. He usually uses NAPA for all of his parts, but I'm not sure if that is where he got the stator or not. I'll look into the distributor you mentioned. I found one from Cardone through Autozone, but they seem to have mixed reviews.