The set-up I remember seeing back in the late 60's early 70s was built by an old racer in my hometown that used the blower case and the multi-belt pulleys he had laying around after he retired. He hogged out the inside of the blower to be able to fit over a stock intake and carburetor. Since it was installed in a car with a hood, all you could see was the blower and belts sticking out of the hood. He kept the gears in the front of the case to give it a bit of a "blower whine". If I remember correctly, the carburetor linkage went thru the back of the blower case (couldn't see when the hood was closed. I don't remember ever seeing him have cooling problems, overheating, etc., but then again, he only drove it around town to and from his house to the "malt shop" all the high school kids hung out at after school and on the weekends. Can you post a few more pictures of the blower case, the back, carburetor linkage, etc.?
Also, from what I can see, it looks like the water pump pully may have 6 belt groves with a belt in the rearmost grove. If so, there is probably a belt that runs from the crank to the 6th (rear) grove in the water pump pully like we did back in the early 70's to drive the water pump without running an alternator. I put a 350 in a '71 Vega, ran one belt from crank pulley to water pump pully, and a 2nd belt from bottom pulley, to water pump, to alternator. The crank to water pump belt was there just in case a 7,000 rpm blast would throw the alternator belt, the water pump would still be turning.
If your setup is similar, all you need to do is measure the belt and just roll in on. Same with the 5 belts that go around the bottom crank pully and the blower pulley.
Please post more pictures....and let me know if I'm waaayyy off base here with this rambling story.