The 9" is a good choice, the gears ratio will depend on the rear tires and the rpm you want to be turning when you go through the end of the strip.
You want your engine putting out full power, close to full rpms when you hit the final timer.
Post what your times are, will be interesting to see.
What rpms are you expecting .
What about the stock block, they are ok but they will twist up with too much owner.
There is a torque plate that helps some, it is mounted on the main bearing bolts, and is suppose to eliminate block twist.
Luck to ya !
4x4, 5sp, Std Cab, Stepside, E4 Red
4” Lift - Coil-Overs, 6” SkyJacker Leafs - No Blocks (Mistake)
31 Spline FX4 Rear Axle, 4.56s and OX Locker, Hurst Shifter w/Optional Stick and "Made by Grev" alignment adapter