5 POUNDS (???) of vacuum. "drill holes in it and things like that" (?).
I'd like to suggest you get a couple of carb books, read them and experiment on a few carbs and you'll see why nobody buys the Predator carb. After several years of building engines, carbs, etc and dynoing engines weekly I now recommend hot rodders buy what works and 99% use Holley carbs on their performance vehicles.