I have the big block large oval ports and the casting #'s are 3993820. Are these one of the better large ovals or not? If not which casting is the best?

Imho, the -820's are good ones.

AND imho, I would ditch the Team G and run a dual plane intake b/c it will make more grunt for you!!

I hope you have the smaller, 1.75" headers b/c they also add the the more grunt thing too..

pdq67

grunt=torque ;) no such thing as horsepower,,,its factored from torque :D

nope got the single plane and the 2 and a 1/4 super comps. looking for some speed not just seat of the pants