As mentioned in a previous post I had rpm fluctuations on my Lyc 540 powered Skybolt. I called Sensenich in Lancaster and asked if they could bench check my governor, which they could for $250. They let me bring it in, watch while it was being tested, answered 1000 of my questions, and let me tour the shop. The governor was bad (after the test they took it apart and measured a number of parts, which were out of spec) and they offered to order a replacement. I asked if they could match the price of Spruce. Not only did they match the price, they gave it to me for $200 less than the price of Spruce, plus they waived their bench check fee. Extremely nice and friendly people, and a great bargain. I have no affiliation with Sensenich but I would recommend them to anyone.
Trex
Trex