what is the best way to get the most torque out of my car. like for example what gears, posi, etc. should i have?

i currently have a stock 396 in my 68 SS chevelle with a newly rebuilt manual TH350 with a corvette clutch pack and shift kit included, no posi, 3.73 gears, 2500 stall.

posi has nothing to do with torque and gears only multiply Torque comes from inside. If you want to do a gear change for more "torque" then swap to a numerically higher gearset but your cruising revs will be higher. The cheapest way to make torque on demand is the bottle. torque = hp/rpm x5252 so 100 shot at 2500 is over 200 ft lbs which will be more then enough to satisfy and fry your tires.
Dane

Aren't you supposed to only use spray at WOT? If so, you shouldn't be getting 100hp at 2500RPM. Right? I'm not a spray guy so am I missing something?

Troy.

You are only supposed to use the juice at WOT - however, you still go between idle - redline at WOT, therefore crossing the 2500 rpm mark (briefly).

Yes wot is supposedly the only time you are supposed to spray otherwise cylinder pressures get to high and detonations occurs, However you may start the spray as low as 2500 rpm from my research.

for about 2 years of racing i had a 2500 stall and a 396 bbc that was going thru some engine changes........my combo took a few steps back and i was very displeased on how my car was performing......finally one day at the track i had enough with my combo and i decided im going to run on the nitrous(i had the nitrous set up in my car for several months but never ran it because i was trying to work out my other combo problems) my car just got done making a miserable 14.99 e.t. at 90 -91 mph.....so upset i open up the trunk and open up the bottle and i told the guys this thing is going to run or its going to blow im tired of messing with it.........lol.......i think the heat got to me that day........

i did my burn out and i did a few blips of the nitrous on some dry hops to purge the nitrous so to say......and i staged the car ran my car up hard against the stall just at 2500 rpms and as soon as the last amber lite up i hit the button and floored the gas at the same time and this baby shot out of the hole........left my car in drive and it shifted at 5500 rpms thru the gears and my end result was a 12.69 at 105 mph..........what a rush.....first time with nitrous on the 1/4 mile and i never turned back and on that day i didnt retard my timming or put race gas in it i just ran on the 92 octane i had in the car...........and that was with 125 nitrous jets........later i moved up to the 150 and never went lower.........i ran the **** out of that motor for 6 years with the stock bottom end before it finally gave way.......to a spun rod bearing at the race track........and i didnt even use nitrous yet that day......lol