Need help with csr water pump.

My son has a 74 Duster with a 360. We are trying to put a csr electric water pump in and keep the heater, power steering and altanator all functional. The water pump has only 2 ports on one side. We were wondering if the by pass hose that runs on a (stock water pump) from the water pump to the intake manafold can be blocked off or do i need to drill and tap the alluminum housing to retain it. Any help would be appreciated.
Brent.