9" vs 10" drum brake spindle question

Thanks, I'll call Doctor Diff on Monday. If I upgrade to 10" spindles, the only other thing I need to change (other than the brake parts) would be the ball joints?
The Stage 1 and Stage 2 kits include these Mopar disc brake spindles. Mopar Reproduction Disc Brake Knuckles for A/B/E Bodies

He does offer large Cobra and Viper brake kits that use 10" drum spindles. These are serious high performance brakes that may be overkill for your intended use. I believe the Cobra kit requires a 17" wheel.