440 melt down

I have a 440 I am kinda unfamiliar with as far as parts. Told it had the 600cfm edelbrock. Issue I am having is on my hot starts the motor has a hard time started and I have to push the throttle down to get it going. Even if there a 5 second interval between shutdown and startup. Was told that I have fuel boiling in the carb and to invest in a spacer. When the engine is cold, 2 pumps of the throttle and she starts easily and even if I stop the motor in adequate time before it warms up, I can stop the engine and start up without pumping the throttle.
Question for this setup is what spacer to go with. I want to stay at the 1/2" thick because of my air filter height. Should I do the Phenolic plastic, open spacer or 4 bored. There's even a divided one. I have seen that the bore spacer adds torque and the open adds HP. Don't know if any truth to that but if so what do you recommend for that 440. Told the motor was out of a mid 70's truck/van and was a mild build. The guy had no info really to share but I believe this motor runs strong.

Thanks