Well I have a promotion to Ssgt(USMC) and reenlistment bonus coming the beginning 2012 so I'm about to either purchase the 426 short block or supercharge my current setup. I'm trying to come up with the best bang for my buck.

Quick Overview: Restomod 66 Plymouth Belvedere
My entire build 6.1 Hemi, 727 torque flight/B &M shift kit/ported and polished intake/ported and polished heads/ TTI long tube headers/ 180 thermostat/SLP under drive pulley/741 housing /3:55. Gears/Detroit True-trac sure grip/power steering delete pulley/ B & M 2400-2800 stall converter non lock up, 90 mm TB with nitrous injector, cold air intake, catch can, Cam specs Intake Duration 267 Lift .583 Exhaust Duration 270 Lift .566.

This is what I posted on the SRT forums and a response I got back was. "You also should think about the capacity of your 727 and rear."
Well I asked about the 727 a while back and found out they are really they can hp and tq in the ranges of 700 to 800 with stock parts and upgraded value body but my question is what will the stock 8.75 rear end with stock axles handle? Also what other weak leaks do you see if any?
People have boosted that the 6.1 block bored to 426ci supercharged will make 600 or better.