THanks Lou, I will try this again tonight, as I did not get full circulation using my muffs, even after attempting to prime it, thats why I asked about priming the pump.
An Alpha drive, any generation, has an open priming system. The impeller, which works as a displacement pump at low speeds and a centrifugal pump at high speeds. To prime, the pump body has a hole through the side of it that bleeds out any air in the pump once the pump is submerged. This also means when you hook up the muffs, once the inlet side of the pump gets water, water should start leaking out of the drive down low. With an intact impeller, no water can get past the pump to the motor when not spinning.
If you hook up muffs, and wonder if the impeller is any good, pull the inlet line off the port side of the thermostat housing, hook up muffs and turn the water on, start the motor. Should be just a couple seconds to water coming out.
If you do not get water, you have a bad impeller or a plugged up hose or oil cooler.