go with the smallest cfm 4bbl carbs you can get. maybe holley 300cfm or 350cfm? they were made for puttin a 4bbl on inline 6's. this guy i knew had 2 450cfm holleys with a weind duel tunnel ram an a points ignition with a stock coil its always ran rich an like crap an on top of it the dummy had a monster circle track cam in it with a 3000 - 7000 rpm range. but i had ran a victor jr with a single 600cfm edelbrock carb on a stock motor an it worked great no heat problems ran a 160 t-stat also