Quote Originally Posted by Buzz View Post
The APT (Adjustable Part Throttle) circuit on the Quadrajets made them highly tunable for decent cruising fuel consumption. Most needed a boss / plug drilled out and then threaded for a removable plug. SMI is one of the best sources I know for quality Q-Jets.
I found an altitude/weather compensating aenoid carb that I played with on my G20. I wish GM had used the barometric pressure compensating aenoid in all of them.