Sorry I'm late to the party... Moving up to a 9.25 will not do you any good for improving launches. You're still stuck with an open diff and no limited slip or posi units available for either the 8.25 nor the 9.25. I am still running the stock front diff on my 1k HP Denali. The transfer case in mine is a BW4485 which uses planetary gears and not the viscous coupler that is prone to breaking. When comparing a 4x4 case to a planetary BW4485, they are the same, the AWD just can't be switched off. No other difference in traction due to the diff still being open.
As for not shredding the front tires, good luck if you're making over 600hp lol... I still rip off the fronts and I'm running 305 Drag Radials but making a ton of torque off idle. You need a stiff double adjustable shock front and rear. The rear needs stiff compression and the front needs stiff rebound to avoid transferring too much weight and unloading that front left tire. Helper bags in the rear help a lot and you can also chain or strap down the front arms to limit the travel.