I managed the group buy on the PCU 5000 guvs on VAF before Doug banished the opportunity of builders doing things for builders and demanded a "cut" whenever a group buy happens... so that is why they don't happen anymore.
Anyways, in the process I learned a bit about who makes what govs and what not.
From what I discovered, there are the old Woodward ones that nobody uses anymore.
There are also the MT's which have been plagued with "surging" issues.
This lead me to looking at the Czech-made one called Jihostroj. See
http://www.jihostroj.com/ for more 411. ANYWHOOOO... they sell it in the US under the PCU 5000 moniker and I sold about 150 of them with Bob Honig from American Engines in California. If you would like one, see him and tell him I sent you.
The PCU 500 has been used in MANY RV's and has a rep for being bulletproof and just simply the BEST! That is why I chose it. See
http://www.pcu5000.com/ for more info on that.
It is a damn shame that I can't do the group buys anymore. They really worked well for the builders.
Oh well, look into the PCU 5000 and talk to Bob. I have his contact info if you can't find him.

CJ