8 3/4 gears

Many thanks to all who answered. I think I'll try Rick's approach. I'm planning on going to 3.73 or 3.91 gears. Summit Racing has steelies and Ralleys in 15" SBP, if I can use those and put some discs on the rear, I'll be happy. FYI, the motor will be a 408" Trick Flow heads and intake, a Racer Brown cam around .685@256, and 10.5 to 1. The carb I have is a QF 750 mechanical secondary. TTI step headers, and MSD E-Curve distributor. A Pat Blaise 727is done, and I'm told a big 3500-4000 converter will work for street and light strip duty.
Paul, are your cam numbers right? .685 lift and .256 duration. If their right it won’t be very street friendly. Your gonna need at least 4.30 gears. Kim