Or, you can install a vac canister to store vac when you're not needing it for brakes.
We put a healthy cam in my brothers 4.8L, he would have lost brakes if it wasn't for this device that is on the booster. It's a 9" or so electric canister that turns on when the vac is low. It's never come on before, it's never had to, but now it turns on and off, kind of neat on a stock truck.
His is an 04 4.8L longbed, like a work truck, so that's why it probably has one.

Also, my '05 avalanche has hydrb., that's another donor truck you can pick from.

later,
allen