Sam with the '96 Impala SS had his gears put in at pro engine. Seems to be working fine for him.
Adam runs pro engine and his number is 381-7898, it's in christiansburg and he stays pretty busy most of the time. Definately give him a deadline for the install, say you NEED it by so and so, or he'll put it off.
He seems to do decent machine work, definately the cheapest labor-wise around. He did some headwork for friends and I in the past, and I currently have some ford heads over there being milled and cut for larger ss valves.