engine help!

[heeroyue2002]

its my other vehicle. actually the only running vehicle i have atm.
1975 dodge d100 with a 5.2 and a 2bbl carb.

the carb is about a year old. i had gotten anew one from rockauto.
when i press the brakes hard or even if i ease into them it shuts off. im having to constantly turn it to nuetral and turn it back on. not sure if its a vacum thing or what.

today i was switching to nuetral whenever i was slowing down and tapping the gas until a green hit. if anyone knows what i can do or if they want to help me in person, id appreciate it.