I'd go with the 1.76 gear set. I wouldn't mess with factory gear set. Get an aftermarket gear set (ex. "super set", etc.) They're good for 750-850 hp in medium weight cars (2200-2500lbs). we have a 1.76 set in a 61 ford falcon running 5.60's 1/8th mile. Tube chassis, all steel body exept hood and deck lid. Guessing 2450-2600lbs. Had it in car for 2 years now and no problem at all. Factory gear sets tend to break after about 125-175 runs on average.
I agree your 1.82 will not last very long at all with your hp rating. You may want to get a aftermarket planetary housing/output shaft assembly. Shorty's tend to twist the splines easy when you get up in hp/tq like your doing.