Re: GM rear gears
 

Pontiac also used some gear ratios that were inbetween the Chevy ratios.

Re: GM rear gears
 

I received this rear with the housing freshly blasted and painted. All of the internals were included in a box. I'll be assembling the rear soon.

The carrier is a 4 series unit, which is one of the indicators leaving me to beleive that this combination was original. Most people who went from a 3 series gear to a 4 series used a spacer plate, very few spent the extra money for a new 4 series posi unit.

I am pretty sure that a BOP ring gear will not bolt onto a Chevy 12 bolt carrier, the 4.33 I have does.


Cheers,

Paul Tholey

Re: GM rear gears
 

Are you sure that the 4-series posi and related gear are in fact Chevy guts ? As JoeC suggests, BOP had ratios typically in between the Chev's. I don't *believe* that Buick had a 4.33, but Olds and Pontiac did. They may be Olds or Pontiac guts that you got in a box with the Chevy housing ?? Justa thought - especially if you never had the whole thing put together as an assembly.

Re: GM rear gears
 

The carrier casting numbers check out as a 4 series Chevy 12 bolt posi. I'm not sure how to determine the date of manufacturing thought.

Re: GM rear gears
 

px;
Been to all of the Hatboro shows, lived in Hatboro for 8 years till last Sept. If you've been to that show, then you must have seen the Huggar Orange '69 Yenko Camaro that was there - usually at the end by DaddyPops.

If your R&P is a chevy unit, and you're sure about the 39, count the teeth to make sure it is not mis-stamp.
M

Re: GM rear gears
 

DUH !!! Casey .....

After thinking about it - I'm convinced it was originally in a Pontiac application. The Chev and Pontiacs both had *12-bolts*, as most know them, but the Olds is a *pseudo-12-bolt* in that it has a 12-bolt cover with a 10-bolt ring gear.

That's my final answer ...... https://www.yenko.net/ubb/smilies/images/icons/smile.gif

Re: GM rear gears
 

Yep, I've seen that Hugger. Where did you move to?

My other sister's 69 Camaro was right at DaddyPops in the 1999 show. It is Midnight Blue with the white stripes (down the smoothed firewall) and has a X-ram in the trunk. Anyways it's amazing we've never talked before. Do you know Mike Clark or Andy Good? I spent a summer during college working next to them. I was working at Shawn Ferrel's "The Vette Shop".

As for the 4.33 gears, Casey's answer is makes perfect sense, although I do find it slightly ironic that both the housing and the ring and pinion have are for 1970 applications. The date code on the housing is before the ring and pinion, for whatever that is worth.

I counted the ring gear teeth and there are 39 of 'em. Since she (my sister who is building the B-M Nova clone) has the 4.33 gear, I think that is what she'll run. After all some comprimises have to be made due to her budget.

Thanks for all of the input guys!

Paul Tholey

Re: GM rear gears
 

Paul;
The HO Y-Camaro is a second owner car, he bought it from a used car lot in December of '69 in Flourtown. Car was orig. from Marshall Chev. in Reading, PA, and is a 4speed with p/s and v/t. The owner has some really cool photos of him racing it at Maple Grove in the '70's.

I have never been to the Vette shop, but have heard about for years. I moved to Douglassville, (out by Collegeville), and am now closer to Maple Grove, the HO Yenko and a Lemans Blue Yenko Camaro in Phoenixville that is also a second owner car believed to have been purchased off of the same used car lot in Flourtown in 1970!
M

Re: GM rear gears
 

That axle could also be from a 69 Camaro. They started coding the 3 letter rearend codes in 1970 model year and many of the late 69 Camaros got it.
I believe that gear was available over the counter and the dating kinda confirms that. Several unusual ratios were sold over the counter and never in a production vehicle.

Kurt

Re: GM rear gears
 

Coupe Chevrolet used to be in Glenside, PA until 1969. They then moved to Flourtown (the next town over). My father knew of Dewan's. He said they had all of the higher end hot cars. It wasn't much of a used car lot- everything was inside- more like a showroom.

As for those 4.33 gears, I just found out that they ARE Chevrolet gears. They are over the counter (Kurt S. you were right!) They were discontinued in 1981. The previous P/N I posted was found on the ring gear. If it would help anyone, the true P/N for the ring and pinion is 3961430.

I must retract the statement I made earlier about the GM 4.11 gears that were for a 3 series carrier. I checked them myself and found out the previous owner of these gears misrepresented them, they are simply 3.73s.

Thanks everyone!

Paul Tholey