Thermoquads and tall spacers

Use AFB rods cut down 3/4's of an inch and re bend to fit.
As far as jets go, IF the under jet well comes loose during rebuild, and only if it comes loose, you can re tap the threads for a Holley jet or AFB/AVS jet.

DO NOT try and remove the plastic well. It is almost a 100% guarantee it'll brake and render the carb a pile of parts.