The best solution I've found for reliably moving large gear is to use Jet Model Products newer valves. They have the highest volume capability compared to anything else on the market; I've tried them all. Even better is to use their PCU. My latest project has very heavy/large gear like yours. I used Tom Cook's PCU that incorporates the newer valves and manifolds resulting in tremendous improvement over the system that came with the purchase of the jet. Take a look at the JMP website, or even better call Tom and have him explain the product. The valves we've used in the past are just not up to the task required by these heavier gear.

Cheers,
Joe Grice