Differences between machine work...Heads
Excellent job Moper pointing out passable work (in that the engine will run) vs. genuine performance work. I had a similiar experience here in Colorado with poor workmanship on a pair of cylinder heads. Large steps where the unleaded seats were installed (although not quite as bad as your situation), guide liners sticking out of the hole, valve spring retainers not seated, etc. The list goes on. Never again will I spend money at that shop. Luckily, I could fix most everything myself.