[Canuck]

I can't help you much with the drive belt pump but you could also consider an electric vacuum pump. I presume Old Mav's mount for "on board air" would work to add a pully vacuum pump. I think that he said this was the location of the vacuum pump on the GUs.

 

[Canuck]

Check the onboard air thread and you will see that all you need is to build a bracket for the vacuum pump under the IP. It will be belt driven if you do this.