Any AFB gurus here??

For what it’s worth, only cars with automatic transmissions have a dashpot to slow the closing of the carburetor throttle plates upon deceleration, a 4-speed manual transmission equipped car shouldn’t have one (and doesn’t need it). 

Unless there’s something wrong with the dashpot and it’s sticking, if they’re setup correctly it shouldn’t make the throttle plates stick open with the engine running. I bought a NORS dashpot from AMARK awhile ago and just recently set it up and it works great on my ‘69 AFB w/ auto trans.