PetDMC-
The chevy 75 will take two 120 MM fans as will the one I am using- ford econoline 85 heavy duty. Chevy has a 5/8" and a 3/4" inlet pipe the ford has both 5/8" another reason I selected it.
I chopped off the 5/8" nubs and soldered on 1/2" copper plumbing couplings with ease. They fit real nice! If you are going to use JB Weld and insert 1/2" hose barbs (brass) inside the heater core inlets the Chevy will work fine.
Oh, I can't tell you the exchange rate on the US / Canadian dollars. If you send me oh..., $1000.00 Canadian, I take it to the bank and let you know how many Yankee bucks I get in exchange! I am always here to help.
Jim