I'm thinking about putting a new carb on my project boat not sure what size carb would be best.It has a Holly on it now but don't know the size of it.The motor is a stock 350.

600 edelbrock is what I would use, they work well(elec choke version) and are easy to tune if needed

Ayuh,...... Ditto ezstriper,... I Love the Carter AFB carbs,....

Easy to tune, 'n very reliable,... a carbon copy of the Merc/ Weber carbs Merc uses,....
The 600/ 650 cfm for a SBC, 'n the 750 cfm for a BBC,....

gm used a 750 cfm q jt on a million small blocks.i would buy a new quick fuel 750 if buying new.they are very easy to tune and fairly priced.what carb&intake do you currently have?

750 qjet

From my own personal experience, I would never buy anything Quick Fuel again. Not saying no one else should or shouldn't.

I'm not sure what intake is on there now but it's a Holly on there just not sure of the size.

what makes you feel that way?did you have a problem with one of their carbs?

Yes, they were nice to deal with, they tried to fix the problem, but couldn't. The carb was dynoed on 4 different motors, single and dual plane manifolds, couldn't get it closer than 1.5 A/F difference between sides.