Find some buddies w/ good running carbs like an original Holley "950 HP" 80496 (1.38" venturi x 1.75" throttle), a Proform or Quick Fuel 950 (1.45" venturi x 1.75" throttle), maybe a Mighty or Race Demon 825 (1.425" venturi x 1.75" throttle), and a decent 850-type from somebody(1.56" venturi x 1.75" throttle), then try 'em out. I have no idea if that's possible for you or not, but it's my suggestion.

IMO, the new "True 950" Holley HP is too big for your application, which is why I was suggesting borrowing & testing smaller carbs.