Q-jet to square bore

[MikeB]

Jon Hardgrove at The Carburetor Shop probably knows more about carbs than anyone in the business. From an article quoting him:

"Jon warns that if you are changing from a square-bore carburetor to a spread-bore model, it's important to use the appropriate manifold. "Never use an adapter," he advises. "For maximum efficiency and performance, you want a manifold that's correct for the type of carburetor you're using."

And I like this comment:

For street-driven cars, Jon suggests spread-bore carburetors like the Rochester Quadrajet and Carter Thermoquad as "the way to fly." He says that some Holley four-barrels fall into this category, but he is not a big fan of Holleys. "Unless you have a racing application, spread bores work best," Hardgrove believes. "Assuming that you don't drive wide-open all the time, you're going to be running mostly on primaries and the spread-bore carb has smaller primaries."