Hi I'm new to the forum My name is Chris. I got a 69 Camaro with a 307 I had a ? my car starts up fine and runs great for about 20mins and then it feels like it starts missing and when U come to a stop u gotta keep giving it gas or it dies.When I turn it off it also makes a loud hissing noise like air getting sucked in I cant figure out what it could be any help would be greatly appreicated Thanks.

It sounds like your choke is not releasing...that's what I would check first.

If it's not the choke, check the gas filter and fuel pump next.

Thanks I'll check that right now I just checked the spark plugs, cap, wires,rotor, and points and they seem fine so i'll check that next really want to fix it so I can drive it before summer ends.

it could also be a vacuum leak

I figured out what it was I have a 2bbl carb so I got a adapter plate so I put a 4bbl carb air cleaner on it and the choke was hitting the adapter plate. I just made it a little higher and now shes running fine thanks for all the help.