I would use a 4:10 gear ratio with the dedicated center section for the 8 3/4 with a steel cap on the drivers side with a spool. either the 742 or 489 case will work, if you use the 489 case get a pinion spacer instead of using the standard crush sleeve . I have used a 3:73, 3;91 and a 4:10 third memebers in my 3400 lbs duster, the car ran real close to the same ET(10:40s) and MPH(128.6) with all three gear ratios Your cars weight is a little more than mine and the HP and torque is a little less so the 3:91 or 4:10 will work fine with your tires, if the tires hold traction at the track