Having never had a hotrod with a posi, I gotta say the powertrax worked out sweet. Thing only takes about 30 minutes to install. No messing with ring and pinion. couple of snags, the 273 12 bolt had 1310 yoke, 331 12 bolt had 1330 yoke, I just did a search here and came up with the correct adapter u joint number and autozone even had it on the shelf. The new rear had a tweeked backing plate, found this out after bolting the tire on and it wouldn't spin. Lastly I installed my exhaust in the carport in a rush so one of the pipes kinda stuck up in the air, since the upper control arm bolt wouldn't clear, I had to pull the pipes, figure might as well fix them too.
Driving was a blast, car revs real quick, kicks you back in the seat, kinda cool when your coming around a turn and punch it, the inside wheel breaks free. Cant wait to take it to the track again, hopefully it will redeem itself and go a little better than 16.1 Jim

I've had my powertrax locker for about three years, and it's the best improvement I have made, after going thru 5 posi units in the past few years, for the money, you can't beat it.