What size carb ?
The formula for figuring out the carb size needed for your motor and RPM is this.
6000rpm X 373cid /3456 X0.85=carb size needed for street use.
6000x373=2238000 /3456=647.569 x 0.85% street factor or V.E.=550.434streetCFM
A 600 vacumn secondary carb would work great,or a 650cfm.
Any one that would like to argu the facts can kindly go to Holley web site or any other carb site and will find this formula,so since they might know more that all of us put together,we will take it that its a good formula,Mrmopartech