Hey Bone's, you didn't say if it was 4150 base or a 4500 base carb? If you have a 4500 base i don't know if you have room for an adaptor plate to a 4150 base carb/hood clearance.The cam you have is actually smaller than a LS7 stock cam. I would think for the street a 750 carb would be perfect, but the choice between a vacuum secondary would be how much vacuum you can pull, so i would suggest a 750 double pumper with progressive linkage, play around with the cams and i'm sure you'll be happy. if you decide to go vacuum secondary then use a 4.0 power valve.
JMO
Zip.