The power tower is fire truck specific. I have sold several of them for scrap iron. You are going to have to build a driveshaft anyway when you remove the power tower. The power tower's sole function was to drive the pump. The easy way to get a little more speed would be an auxiliary with OD. The hydrovac brakes will be adequate if you rebuild all the components. The small block GMC engines, 228 through 302, are comfortable running 3400 all day long. We ran them like that 50 to 60 years ago when we used them to haul gasoline. There is no reason to run them any slower today. A .80 OD will make the thing go faster than you probably want to drive it any way.
