Is there a visual way to tell these rearends apart while still in the car.

I think one clue is the 12 bolt cover. A chevy cover has sort of an eyebrow bulge, where as the BOP is smooth. I also think a BOP has notches on each side.

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DG
Springfield, Ohio


My 70 Malibu http://www.wright.edu/~adams.41/chevy.htm
dga@erinet.com
TEAM Chevelle Member #0086
eBay username: dg98adams

Are these notches at the bottom. Not sure what you mean by notches. I am currently looking at one in a 72 Monte Carlo. Just want to be sure.

By notches, I mean there is a "c" shaped notch on each side of the 12 bolt cover. Car Craft did an article a couple months ago on this.

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DG
Springfield, Ohio


My 70 Malibu http://www.wright.edu/~adams.41/chevy.htm
dga@erinet.com
TEAM Chevelle Member #0086
eBay username: dg98adams

As far as Oldsmobiles go, Old's 12 bolts have a 10 bolt ring gear and bolt in axles. The bolt-in axles are a dead giveaway. Also, as said above, the stock Old's cover doesn't have the arch shaped bulge to direct gear lube to the bearings.

DG, you're thinking about the BOP 10 bolt cover. The Olds 12 bolt looks almost like a Chevy 8,5 10 bolt. Both have the squared off ears at the bottom of the housing, as you're looking at the cover. The Olds 12 bolt cover has 12 bolts and is almost perfectly round. The Chevy 12 bolt has a cover that is slightly triangle shaped, for lack of a better description. I know, because I spent a Saturday afternoon with an Olds 12 bolt six inches from my face while trying to find the build code. I thought I had found an Olds 8.5 inch 10 bolt until I crawled under it and looked at it a little closer. The Summit catalog has a picture of the Chevy 12 bolt cover gasket in the section where they sell the Richmond gears.

[This message has been edited by Randy Mosier (edited 05-25-2000).]

Thanks for the info. One other question are theses BOP 12 bolts worth buying?

Olds 12-bolts are strong, but there is limited availability of different gear ratios, and gears are very expensive.

Turns out this is a 12 bolt chevrolet, and it only cost me a 100 dollars. Again thanks for the info.

That is a pretty good deal.

Steve R.