How big of a 4 barrel on a stock 1970 318?

1405 600 CFM Edelbrock with manual choke or 1406 with the electric choke.
Agreed, very simple carburetor and very reliable and easy to work on for the hobbyist. I've went with both the carburetors mentioned and went with the Holly because I was green with my mean 318 back when I was a teen and I didn't know any better. And I now that I've have a little bit more experience with carburetors if I was going for some serious Max effort I would definitely go with the Holley carburetor because of its adjustability but the Edelbrocks make great horsepower and make easy adjustments for the hobbyist and are not prone to problems. pretty much get them set and you're good to go. I am right now about to throw one on the 360 with a stock 4 barrel intake just like you have that had a 2 Barrel on it and I have a free Edelbrock carburetor that's some ding dong for some stupid reason figured it was no good and bought a new one. They rarely if ever go bad especially if you just had it like he did lol I can't stop, pay a hundred plus dollars to have someone rebuild it and then still say there's problems with it and go buy a new one and still have the same problems and give this one to me O boy. I LOVE MY CHEVY FRIENDS!!!
You guys know I try and help, but when I do and am told "I got a brain !" "I'm ot stupid" that's more than I need to keep my mouth shut and gladly smill and accept what looked like a brand new carburetor that had been just rebuilt oh yeah that was given to me in the box from the brand new one so it almost looked as if it was a brand new carburetor and a brand new box! But the real coup de gras will be hopefully here in the next month or two when I finally had the track together and I take the hour and a half drive to his house with that carburetor on the truck and drive it back home! Oh wait a minute it's getting late that might have been a whole different story....