I'm trying to determine if my car has the original rear end. The stamping reads LAB 092. There's a casting number of 1235197 and another code that looks like CFO. Does anybody know what these mean? My car was built the first week of April 1971 and has an automatic. Thanks.
Chris, I know a 3.42 posi was LWB in 71 so LAB is probably correct for another ratio. I will check my stuff later for that code unless someone beats me to it. The 092 is a date code. Maybe 9th day of the year 2nd shift or 92nd day of the year. Check and see if there is a another number after the 2. A 1 would be first shift and 2 second. I think my car had three numbers for date then another number for shift But I will double check. I think mine reads LWB 155 2
Dave and David, Thanks for your help. Based on the date, the rear end appears to be the original. Now if I can get all the pieces back together, it'll be a car again.
No problem . I just looked at mine again. Date is 084 1. March 25 only a week before my car was made. Not sure if the 1 was 1st shift or 71? Are you going to replace carrier with posi?
Dave, I hadn't thought of putting posi in the car. Is that something that's fairly easy to do? Will it fit in the existing casing?
Chris, I believe you can use the existing housing you just need to change the carrier and gears maybe a few other small parts. You may want to keep asking as I am not 100% sure on this. If you swap I would suggest an Eaton posi unit. I used one in mine and they are real nice with solid and quiet operation. You can also still get GM gears for the 8.5 in different ratios. Check Randy's ring and pinion for best prices on Eaton and GM gears.
Chris, why would you want to spend the money on a posi? A 3.08 gear set is perfect for what you are doing, your new cam, carb and entire set up. If your gears are in good shape there is no need to swap anything out. A posi is nice if you are going drag racing but for around town cruising on dry pavement you don't need it.
