Thats a nice homemade rig there misminoff, wish I would have seen that earlier. I happed to buy one of these that I found to do the same thing. It wasn't too expensive either.

msiminoff wrote:
Is there an easy way to deflate that I'm missing?
I made a simple assembly that allows me to inflate/deflate two tires at the same time while maintaining equal pressure, ceteris paribus, in each tire. Of course my setup is for a SRW truck, but it could easily be reconfigured for a DRW. Here's a pic…

Note that the tire chucks I used are the lock-on type so there's no need to hold them in place while inflating/deflating.
Cheers,
-Mark