Help please, decoding car

[bcmiller]

You need to look at the rear axle in the area where I told you to look.  See the picture I linked too.  The numbers will be stamped on front of the passenger side axle tube, not cast into the metal on the center section.

As for the engine code, look where I told you to look.  On the pad of the block, in front of the passenger side cylinder head.  Alternator may be in the way, but the brake booster is no where close to this area.

[KERR]

ill look again,   but those are the only numbers i saw on the rear end..     I cant see any numbers on the pad, its got ac line, alt etc in front of it.  maybe this weekend ill have time to dig into it

[69Z28-RS]

stamped code on the rear axle:   Look on the front side of the passenger side axle tube, about half way between brake and differential.    You'll have to clean the tube and use a bright light to see it...

Engine pad:   look down behind your alternator, straight down to a smoooth front pad on the engine block, adjacent to the head.  Again, you may have to clean the pad, or use some chalk to see the stamped codes.

[KERR]

well i looked again last night,   i guess im missing a number on the rear axle.   It looks like BP 04256.     which by that chart on here is a 10 bolt, with high gear ratio,  so some has swapped out the gear at some point.  it turns 3500 rpms at 70 mph. 

as for the engine pad,  it's either an aftermarket block ?  or there is so much paint build up on it that i cant see or feel any numbers.   i guess at some point ill take the alt off and get a razer blade or something to scrap the paint off.. 

[bcmiller]

Rear axle is probably BP 0425G1 - so the assembly date of the housing was April 25.  Your car was assembled the first week of May, so the housing may be original to the car.

The BP code is 2.73 - you probably saw that. That ratio was commonly used in 1969 for the 230, 250 and 327 cubic inch engines when a Powerglide transmission was used. Probably with the 307 engine too, but I can't confirm that at the moment.  My guess is the original engine was a 307.

What size rear tire do you have?  I can figure out approximately what gear ratio it has now if you let me know.

With a 26 inch diameter tire, a 3.73 rear gear will give you about 70 mph at 3400 rpms.

[cook_dw]

The BP code is 2.73 - you probably saw that. That ratio was commonly used in 1969 for the 230, 250 and 327 cubic inch engines when a Powerglide transmission was used. Probably with the 307 engine too, but I can't confirm that at the moment.  My guess is the original engine was a 307.
 

Same as my 69.

307 - glide - 10 bolt mono with 2.73 gears.

[KERR]

Id have to look on the tire size to be sure,  i know they have been switched out and the rear are wide,  i get some rubbing sound ever now and then..  im not sure what the height is,  when i popped the beauty rings off to wet sand i noticed its a 15' wheel,  i think the  tire said 265,  but i didnt pay a lot of attention.   My daughter was night to point that it has different tires,  " hey dad,  why those tires have different names?  long puse,  i guess the tire store guy cant read"

I know its not to in the 4:56 range,   the vette had 7.70 X15 and i went to a radial from cooker in a 205-75.   in 4th it turns abour 42-4300 at 65 with the 4 speed..   so in the camaro thats probably a 3:73 as you said

[janobyte]

Search the web a little bit " racer's math "   Calculations are done  , just plug in your numbers.  try csgnetwork.com   Engine RPM calculator.

[KurtS]

As stated, that's a monoleaf axle. So it wasn't a 350 car originally but a 307.

[KERR]

thanks for all the info..  i guess ill go back to the original game plan of building what i want

[janobyte]

All good And looks like your kids are having fun with Dad out in the garage--win win !   BTY ,we all build what we want, or they would all look the same