Mopar's used a similar carb to the quadrajet,(being a spread bore)They were called thermaquad's & I believe they were 800cfm or maybe a little bigger. AFB carbs had vacuum secondaries,weighted secondaries.or Carter carb called the AVS,the secondaries had an adjustable spring.I tried a Carter AFB 450,it ran OK on my 250 ,but nothing compares to running three sidedraft Webers.
I also ran Holley 350 two barrel,just OK,650 Quadrajet,just ok,625 AVS Carter just Ok. Running Side drafts Webers are awesome,just time consuming with jetting them.It is really a day & night difference!
