I just bought a new 350 bored 60 over, it has a pretty big cam, ported high output iroc 305 heads, and a high rise intake manifold. It came with a 750 cfm carter carb...but it's been sitting for 2 years. Do I need to rebuild it or should i just put some kind of injector cleaner in my gas? I also have a fairly new edelbrock 600 cfm carb with less then 500 miles on it. I was thinking I could just use that carb. Would the edelbrock be enough carb for my engine? the engine has around 350-400 horsepower.

 

The 600 cfm carb should do fine. A useful equation to figure out what size carb you need is:

carb cfm = (engine cid * max rpm * VE%)/3456

High performance engines have a VE of around 85% and assuming a 6,500 max rpm:

carb cfm = (360*6500*.85)/3456 = 575

So, the 600cfm carb should work fine for you. 427 Corvettes used a 585cfm carb from the factory and put out 390hp. Most people oversize the carb, when a smaller one will do just as well.

If you do decide to go with the 750 you should definately rebuild it. It's cheap to do and it will save you headaches if it ends up needing to be rebuilt.

 

I've read that stock engines of the smogger era were closer to 75-80%, and a warmed over small block tended to have a VE closer to 90-95%. And some race engines are into the 110% ve range NA(not sure if thats possible though)

Personally i think the carb would choke it a little or alot on the top end. I'd go with atleast a 650cfm carb.

For a daily driver occasional racer 600 will likely be big enough.

 

Thanks a bunch...I'm going to go ahead and get a rebuild for the carter and run that after it's rebuilt. Thanks for the input.