WANTED ! BOP 10 bolt 8.2 posi for a 66 Bonneville

jsr · Veteran Member

WANTED ! BOP 10 bolt 8.2 posi for a 66 Bonneville

63gpman · Addicted!

Should be a 8.875 under that Bonneville unless someone changed it out?

jsr · Veteran Member

63gpman wrote:
Should be a 8.875 under that Bonneville unless someone changed it out?

hmmm...i thought all Pontiac's of that year came with 8.2's ? I'm going to have to dig deeper and pop the cover and measure up and see.... so you believe its a 10bolt ring gear but 8.875 diameter ....do you know this for sure ? i have looked every where on the net and no mention of 8.875's on 66 Bonneville's , every place i look , summit racing , pontiac pages etc all say it should be an 8.2......proof of the pudding is to look and see.....i will stay in touch , thanks for the heads up !

jsr · Veteran Member

.....it has a 8.75 or 8.85 ring gear and 12 bolts holding it on !

jsr · Veteran Member

....so does this mean that chevy passenger car 12 bolt 8.875 ring and pinion will fit in my axle ?

427carl · A Poncho Legend!

yes you will have to have the right carrier for posi-traction If you need a posi, you are probably racing it So you'll need a 4 series carrier for 4:11 gears

63gpman · Addicted!

Yes, 8.875, no question about it

63gpman · Addicted!

jsr wrote:
....so does this mean that chevy passenger car 12 bolt 8.875 ring and pinion will fit in my axle ?

Not the same animal as the chevy gear set, you need a P8 gear seat. Hard to find in higher, numerically, gear ratios. 3.55 is (or was) being made by Fabcraft Metalworks. A series 3 carrier is what you want for any gears that are 3.23 or higher numerically

63gpman · Addicted!

What gear ratio are you looking for? Carriers are as follow. Series one 2.28-2.56, Series two 2.73-3.08, Series three 3.23-4.33. You can use a series two carrier with Series three gears, buy you will need a spacer. The only aftermarket gears are 3.55 through Fabcraft but are intended to be used on a series 2. Used gear sets are hard to find above 3.08. I am also in the market for a 3.23 or a 3.42 for my 66.........................yes, it is more difficult than it needs to be, but it is a super strong rear and can handle a lot of torque!!

jsr · Veteran Member

63gpman wrote:
jsr wrote:
....so does this mean that chevy passenger car 12 bolt 8.875 ring and pinion will fit in my axle ?
Not the same animal as the chevy gear set, you need a P8 gear seat. Hard to find in higher, numerically, gear ratios. 3.55 is (or was) being made by Fabcraft Metalworks. A series 3 carrier is what you want for any gears that are 3.23 or higher numerically

Thanks every body for the awesome information , if i found a higher gear set (3.55 and up) can't i just machine up a ring gear spacer for my series 2 carrier and shim the rest !

63gpman · Addicted!

Yes you could. I believe that Mr. Gasket 903A spacer kit did exactly that and included longer bolts.

jsr · Veteran Member

.....to answer my own question i can just use a spacer on my series 2 carrier .....

jsr · Veteran Member

ok next question .......does any one here know if can swap my 12 bolt ring gear 8.875 diff out of my axle and install something with a bit more popular (GM 8.5 or 8.75 for example ) ? i can see im going to have to pull my diff and pinion out and try and match up parts ....being a good machinest im sure it can be done with minimal work ....

jsr · Veteran Member

63gpman wrote:
What gear ratio are you looking for? Carriers are as follow. Series one 2.28-2.56, Series two 2.73-3.08, Series three 3.23-4.33. You can use a series two carrier with Series three gears, buy you will need a spacer. The only aftermarket gears are 3.55 through Fabcraft but are intended to be used on a series 2. Used gear sets are hard to find above 3.08. I am also in the market for a 3.23 or a 3.42 for my 66.........................yes, it is more difficult than it needs to be, but it is a super strong rear and can handle a lot of torque!!

Im looking to put 4.10 or 3.75 gears in it as its a big heavy car and i only use it for bashing the streets in , no highway stuff ! im going to find a 12 bolt chevy 8.875 gear set and see whats going on with it ....i have a two old gmc 1500 pickups with ten bolt rear ends .....ill strip one down and see what i can do , you can get loads of parts for those . i can see a lot of messing about with spider gears , spacers ,C clip and non c lip parts , odd bearing sizes , pinion yoke shimming etc is going to be going on !

63gpman · Addicted!

Agree, you are likely best to drop a ford 9", 96 impala SS rear or something of the like and modifying it to work vs trying to find that gear set, also it would be nice to shorten it overall by about 2-3" so you can get a decent wheel under it. These were non c-clip axles and are a good rear, but 3.42 was it from the factory, however you could get 3.73, 4.11 and so on over the counter, but they are not easy to find. 3.55 is the only gear set on the market, so if that does not work for you, I would see about doing some type of swap. The good news is that the 3.55 set is made to work with a series two carrier, the bad news is that it is like $450 USD. Good luck and keep her on the road!!

jsr · Veteran Member

63gpman wrote:
Agree, you are likely best to drop a ford 9", 96 impala SS rear or something of the like and modifying it to work vs trying to find that gear set, also it would be nice to shorten it overall by about 2-3" so you can get a decent wheel under it. These were non c-clip axles and are a good rear, but 3.42 was it from the factory, however you could get 3.73, 4.11 and so on over the counter, but they are not easy to find. 3.55 is the only gear set on the market, so if that does not work for you, I would see about doing some type of swap. The good news is that the 3.55 set is made to work with a series two carrier, the bad news is that it is like $450 USD. Good luck and keep her on the road!!

.....your are 100% correct in your assumptions 63'....i'm on the scout for a different axle !