My best ever with the 383 was a 12.56 at somewhere around 107. This is in a 70 RR, at the time it was with the 3.73 741 case rear and a 23 spline A833. I was running slicks and collector extensions on the headers, otherwise just as driven on the street. The clutch was an old Hays Pro Stock that kept your left leg in shape. Guessing with me in it the car is about 4000 lbf. Eventually blew up the rear but what went was the left (stock) axle shaft, broke clean off, twisted the right shaft, broke teeth off the spider gears inside the Sure-Grip, and you could see where the ring gear had been hitting the housing. The ring and pinion were fine, sold them to someone here on Moparts and as far as I know they are dong fine.

Now the car has a 452 built by DRAM. The rear is a 4.3 Strange 60 with a Tru Trac. Still the original rear springs, with clamps on the forward sections. Same tranny. Clutch has a Mcleod 800 disc, which has organic facings on the pressure plate side and kevlar puck like thingies on the flywheel side. Pressure plate is a Mcleod that was reworked by 4speedsavoy's clutch guy. At the time the car had the 383 (blew it up not long after installing the new clutch and scattershield) so hopefully it will still work with slicks. Have not had a chance to take it to the track yet. Have heard that the track is open the 5th February so hopefully will get to test it that night.