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68 Ring Gear Decode

10K views 6 replies 3 participants last post by  bcm66  
#1 ·
Recently bought a 68 RS/SS with BR1031G stamped on the axle tube. Last night I removed rear cover and found the following stamped into the ring gear:

2 GM 3862691 14 43 10 7.

My research indicates a 2 series carrier with a 3.07 gear ratio manufactured in October 1967 for the 68 production year, which matches axle tube stamp where BR = posi 3.07:1.

Is this correct? Also, in going through "Chevrolet by the Numbers" I have not been able to find anything regarding ring gear part number 3862691. Can anyone verify?

Thanks!
 
#2 ·
Jeff, that's the correct casting number for the ring gear (3862691), but you should have a 3 series posi unit (ED30140), not a 2 series.

67-69 12 bolt 2 series ratios - 2.29 (1969 full size passenger car), 2.56 and 2.73
67-69 12 bolt 3 series ratios - 3.07, 3.08, 3.31, 3.55, 3.73 and 3.90
67-69 12 bolt 4 series ratios - 4.10, 4.56 and 4.88

Ed
 
#4 ·
Jeff, that's the correct casting number for the ring gear (3862691), but you should have a 3 series posi unit (ED30140), not a 2 series.

67-69 12 bolt 2 series ratios - 2.29 (1969 full size passenger car), 2.56 and 2.73
67-69 12 bolt 3 series ratios - 3.07, 3.08, 3.31, 3.55, 3.73 and 3.90
67-69 12 bolt 4 series ratios - 4.10, 4.56 and 4.88

Ed
I assumed the "2" before the GM meant a 2 series. If the 2 stands for something else, where would I find the ED30140 number? Just closed up and am puting gear oil back in...
 
#5 ·
BR is a 12 bolt 3.07 posi code.
http://www.camaros.org/drivetrain.shtml#AxleCodes

43/14 is 3.07 and 10 7 does indicated October of 67.

I think 3862691 is the correct part number.

Tell us more about the car. 396 or 350 car?
Big B,

Car is a 350, Grotto Blue, 11A build date, 4 speed. Showed up here on some discussion boards years ago (via ebay) and there was some speculation as to whether or not it was a true SS. Had a "Magic Mirror" trim tag along with a federal conformance tag as well. Most likely means it was meant to be an export vehicle. When I got it home, I poked a hole in the cardboad portion of the glove box and found the original owners manual and protect-o-plate. Name on the protect-o-plate matched the name on the original title, which was a N.J. title issued in May '68. The question is where was the car between 11A and May 1968? Owner's manual had the dealer stamp. Kurt S has a copy of the protect-o-plate. A review of all numbers against the plate revealed the block, tranny and rear were original to the car, with partial vin's matching on the block and tranny :hurray:. Motor and rear assembled 1031. Heads dated J 23 7 and J 24 7. Now the gear ring dated 10 7. Very excited to have this car! Options include head rests (3 holes) speed warning, J52 brakes, console w/guages, tic-toc-tach, 8 track in-dash stereo, RS package, and probably something else I left out. Pic below (not my residence):

Image
 
#6 ·
Jeff, the ED 30140 (or 30140PM1) will be cast into the posi carrier itself, so inspect it before you pour in the 90WT!!

The question is where was the car between 11A and May 1968?
It sat on the lot until someone purchased it. Remember, the date stamp in the Warranty book is when the car was placed in service (sold).

By the way, PM me the VIN so I can update the databse.

Ed