Dipstick Blowing air??

Chasing down a stalling problem on my carbed 87GT, it will start and I can keep it running by feathering the gas, but when I blip the throttle rpms raise, hang for 4 secs and then stall out unless I feather the gas. I also heard a hissing from the engine bay. After I turn off the car the hissing would continue for a few seconds so I check and there is air blowing out of the dipstick tube, fairly good amount

Inoperative pcv maybe? put a oil fill breather and it stops hissing but the throttle hanging/stalling is still there

again its on a carbed car

thanks

forgot to mention, new lower has no pcv provision. Would an oil fill breather suffice?