I have an 8.5 rear end (has dog ears on bottom, 4 knuckles where axle tube enters pumpkin, 1.625 pinion shaft and 11/16 ring bolts). My questions are as follows

1. I am going to put a Tremec TKO 5 speed with .64 5th gear. I am making a corner carver out of my 69 camaro. I am trying to decide between 3.42 and 3.73 rear gear static ratio. I would like to hear from people on this forum with advice on which one to choose.

2. Will any carrier for an 8.5 chevy rear work or are there differences? The only stamping on the pumpkin is 1235542n which I believe is from a 72 Nova. The carrier that came out of it is an open carrier with 3.08 gears. The casting numbers on the carrier are 1234459n which I cannot find any cross reference for. I am wanting to buy a posi carrier for the rear end.

3. Which brings me to my last question. Are there any posi carriers I should avoid? I have read that the Gov-loc is not so good which would be unfortuanate given their low cost.

Thanks in advance for any advice

 

I am not technically inclined so I can only advice on question #1. If you plan on creating a corner carver then I recommend you use a 342 instead of 373 as it will be easier to get the power to the ground when coming off a corner. With a 373 you would have to be more careful with the trottle or you would end up spining your wheels and fishtailing rather than accelerating.

Also you are more likely have low profile tires on a cornering car. 373 gears could limit your highway gas mileage at high speeds even with an overdrive.

I have 342 gears on my Camaro with 245 50 R16 tires. I cruise in drive on my TH350 at 70 mph at 3500 rpm roughly.