Chevy to BOP differences My 66 special has an 8.2 ten bolt with a 2.90 or so gear in it. I have an 8.2 I'm removing from my 70 camaro that has a good 3.31 gear on it. Will the later 8.2 posi carrier fit in my 66 housing without issues? I keep reading about differences in housings and this whole Buick thing is nearly as bad as my 69 Dart is. I never thought ANYTHING could be as bad as a mopar but I think I might have matched it!
I know somebody on this board knows more about this then me,but I think the Buick has coil springs and the 68 Camaro has leaf springs.The internals might be the same,don't know for sure.Bruno.
You can install 8.2" Chevy guts into an 8.2" BOP housing. I have done it. There is a special pinion seal needed. Not rare,just a different one. I'll get the part number.
Thanks Brian. Seems like gm would have used the same housing for all the a-bodies but not so huh? I just have a decent posi and gear in the old 8.2 from my camaro when I decided to go 8.5 with a 3.42. Hate to waste it.
Will not work anyway.... WELL not entirely true.... But it might be a headache for someone that does not do this stuff all the time. Chevys carrier off set on the ring gear flange of the posi unit will be different than for your BOP 2.93 ratio to CHEVY 3.36 ratio there was no 3.31 for 10 bolt Chevy it is 3.36...and no 2.90 for BOP it was 2.93. Anyway BOP 2.93 is on a mid series carrier only BOP has. Chevy just has High and Low carrier. ....Sooo that means you will need to offset the carrier pretty far to the driver side causing a more and less spline engagement and sometime you run into a cross shaft with an axle end... I have seen BOP rears come in with wrong gears on wrong series carriers and it just kills the cones and wipes the posi unit as the axle will not fully engage both pieces of the cone side gear only the clutch / cone hub... BEST not to do it unless your willing to handle all the details of correctness that go with it. It is your choice though your car and parts. Just trying to help with the knowledge part and what is coming at you. Jim J D
Jim, i did not have to do that. I had a customer with a 72 Chevelle,that wanted to put 3:73's and a posi,into his existing 8.2" Chevy rear. However,the housing was pitted real bad,and even had rust holes in the spring perches,so there was no way I was going to build that. I had an 8.2" BOP rear,from a 72 Lemans(a Pontiac 8.2") core that was real nice,so I installed the Chevy 8.2" guts into that housing. I think I did that about 10-years ago,and it's been fine.The carrier centered in the housing. It was not offset. The pinion seal that I used was #473440.
what ratios did you use? 10 bolt 8.2 chevy carrier break is 2 series 2.56 2.73 same as the BOP 64-67 2 series 2.56 2.78 3 series 3.08 3.36 3.55 3.73 4.10 4.56 4.88 is the same as BOP (4 series) 3.36 3.55 3.90 4.33 bop 3 series is all by itself 2.93 3.08 3.23 Chevy does not have a mid series carrier BOP carriers step up by 1/8" where as Chevy is about a 1/4 jump With bolt in axles you can move the carrier from left to right in the case as they are not limited to stay center as much as c-clip axles are which will offset the drums and make one side hang out further that the orther side. Bolt in axles are always going to have the same break offset as the axles are not affected by c-clip orientation to the side gears location in the posi unit. But as stated earlier... in the cone units they have 2 piece cone/ side gear and a 1/2" will really mess up a posi unit if you have to slide the carrier over too far in the housing case. Now if the unit is a EATON in the Chevy and not a BORG Warner the axle engagement in the Eaton is not critical as it has A one piece side gear spine. The Borg unit is a cone unit and some early Chevys did use them ...you will have this 2 piece side gear cone split to worry about...It is something that I would need to show people to really get a grasp on it. It would be as if you put a 64-65 axle shaft in a 67 68 69 housing...it will not engage both pieces of the posi units guts... causing a burning up of the cone/ cones. So all you did was get a 3 series posi and 3.73 gears and it all worked because you used the correct series parts with the posi etc. BUT if you look at what Bygblok wants to do he can not. he has a 2.93 gear which is the MID series carrier gear which CHEVY does not have so his carrier will have to be moved off center more than it should and as stated may cause bad axle spline engagement on one side compared to the other. - shims could be .170 on one side while the other side could be .300 when normal is like .230 - .250 ish on each side. Hope you can visualize it as i explained. reference the posi unit flange offset measuring picture i attached... Jim J D
I know about the split in the cone units,but I don't mess with those anyway.If you pull an axle shaft from a cone unit,you can see a perpendicular line on the splines.This is the split line that you are referring to.No,you would not want to move that carrier to the left or right. The way I read his post,he had a Chevy 8.2",with 3:36's,and I am assuming the 3:36's have a matching posi unit attached to them. I am also assuming the the 8.2" Chevy posi unit is an Eaton,with clutches. If I interpreted his post correctly,then yes,you can take that 8.2" Chevy 3:36,and the matching Eaton posi,and install it into the BOP 8.2" housing. The pinion seal might be different than the one I used in the 72 Pontiac housing. Maybe the 8610 seal.
I can't remember whether my carrier is an Auburn or an Eaton to be honest. It's still in the 8.2 as of now and I just thought it'd be an easy swap to do. I can BUY a new carrier for the Buick, but if I had one that fit it with good gears on it why spend if it's not needed. May give it a shot just to see if it'll work. Thanks for all the help and suggestions.
Seal...There is not a cross over seal for the Pontiac housing BUT the early Buick and Olds 8.2 1964-1966 early can use the standard Chevy pinion seal in place of the Buick / Olds 8620 seal If you have a Pontiac housing you will need a machined press on sleeve for the yoke to make it the same diameter as the 2043 seal in the Pontiac 8.2 rears. We have these press on sleeves. It is necessary to know what actual 10 bolt 8.2 rear you have under your car as to the parts you will need for the 3.36 Chevy gears and matching posi into the BOP housing. Quoted ' I can't remember whether my carrier is an Auburn or an Eaton to be honest. It's still in the 8.2 as of now and I just thought it'd be an easy swap to do. I can BUY a new carrier for the Buick, but if I had one that fit it with good gears on it why spend if it's not needed. May give it a shot just to see if it'll work. Thanks for all the help and suggestions. ' It will not matter what POSI unit you have as long as you are using the gears with the posi. You will need to correct the carrier shims and might need a pinion shim adjustment also. JD Jim
Jim, The seal I used was #473440. It was somewhat of an oddball. The housing I used was a 72 Lemans 8.2" P-type. Since he likely has a Buick 8.2",he won't have that issue.
