Denny, I am the one working on 52Stoves' truck. The vacuum wiper is something we have been considering, it isn't something we are working on.
It is an interesting topic, I've been looking the fuel pump/vacuum source and an altenator with vacuum but perhaps some testing as you suggest is a good idea.
Let me kick some things around, I'll post the ideas/methods/pieces and maybe we can do some kind of a definitive tech piece.
