I noticed basic (non posi, non rear disc) 69 Camaro open rears were coded with the letter B or the letter P as the first part of the rear code. Do these letters also designate whether it was a 12 bolt or 10 bolt. I noticed all (not many) the 12 bolt rears I've seen for Camaros start with the letter "B". Are there any 12 bolts (for Camaro's) starting with the letter "P"?

Okay, kinda found my answer from a more detailed search.

http://camaros.net/years/69/69rearcodes.html

MacNeish has a chart in his book (1969 Z28, SS396 book) with two open 3:08 gears rear end listed as "PA" and "PG". Did GM make a 69 Camaro 12 bolt 3:08 gear rear? All the "P" codes listed in the above chart are for 10 bolts.

Joey they sure did make a 12 bolt 3.08 its code is BL and I have one in my car.
The info. on www.camaros.org (http://www.camaros.org) shows this for me.
graemlins/thumbsup.gif

Originally posted by click:
Joey they sure did make a 12 bolt 3.08 its code is BL and I have one in my car.
The info. on www.camaros.org (http://www.camaros.org) shows this for me.
graemlins/thumbsup.gif Click: All the data I have shows the BL as a 3:07 12 bolt. (MacNeish's book, CRG, and Chevy by the #'s)
The reason I ask is because a post was written a while back describing the ways you tell a big block pace car from a small block pacer. Someone replied that the small blocks normally had 3:07 rears and the big block normally had 3:08. I can't find any data showing a factory 3:08 12 bolt Camaro rear. All pace cars came with a 12 bolt. Please post any info you have showing a original 3:08 12 bolt. I can't find it on Camaros.org
Thanks for the help.

Joey, Im bad... mine is a 3.07 as are most the 12 bolts such as you found in Colvins and CRG.. when the math is done dividing the gears the 3.07 is a bit more, I dont recall but like 3.0743 or something like that. I think alot of folks like myself round the numbers up to 3.08. Maybe it sounds better Im not sure. the BL is 3.07 and thats coincides with CRG data as well. You woke me up on that one this morning, only had half a cup of coffee when I realized the numbers I talked about were off by .01 graemlins/clonk.gif

No problem Click. The main reason I'm posting is I didn't want people to go to buy a big block 69 pace Camaro and insist the rear (BL)was only put into the small block cars and walk away from a possible true big block pacer.
I was only trying to correct some information someone else posted.

As far as I know the only way to tell if a Z11, Z10 was a big block car, is to go by the paperwork (if available), original engine (obvious), transmission, AC evap or heater core, original engine frame mounts, and possibly the front coil springs (this is not always true). As I see it, there is no official 3:08 coded 12 bolt rear.
Other stuff like the radiator, etc can tell a lot about a car, but most of the time those things are swapped long ago. graemlins/thumbsup.gif