rearend code

[pink aar]

Does anyone know the rearend code for a 70 aar with a 3.55 gear. This code is on the built sheet. I found one of a 3.91 gear which is 078. But I can't find one for a 3.55 grear . Thank for the help. This is on the right side of the axle ,CORRECT??



Know nothing, but willing to learn.

[Cuda Cody]

@pink aar   076 is the one you want.   Here's all the E-Body codes in case anyone else is interested.

Also, there are some date codes on the 3rd member and axle too.

008   7 1/4 Rear Axle 3.23 Ratio (Open) 10" Drum 1.875 Pinion & 7260 Yoke
010   7 1/4 Rear Axle 2.76 Ratio (Open) 10" Drum 1.875 Pinion & 7260 Yoke
048   8 3/4 Rear Axle 2.76 Ratio (Open) 10" Drum 1.875 Pinion & 7290 Yoke
049   8 3/4 Rear Axle 3.23 Ratio (Open) 10" Drum 1.875 Pinion & 7290 Yoke
050   8 3/4 Rear Axle 3.23 ratio (Sure Grip) 10" Drum 1.875 Pinion & 7290 Yoke
073   8 3/4 Rear Axle 3.23 Ratio (Open) 11" Drum 1.875 Pinion & 7290 Yoke
074   8 3/4 Rear Axle 3.23 ratio (Sure Grip) 11" Drum 1.875 Pinion & 7290 Yoke
075   8 3/4 Rear Axle 3.55 ratio (Sure Grip) 10" Drum 1.875 Pinion & 7290 Yoke
076   8 3/4 Rear Axle 3.55 ratio (Sure Grip) 11" Drum 1.875 Pinion & 7290 Yoke
077   8 3/4 Rear Axle 3.91 ratio (Sure Grip) 10" Drum 1.875 Pinion & 7290 Yoke
078   8 3/4 Rear Axle 3.91 ratio (Sure Grip) 11" Drum 1.875 Pinion & 7290 Yoke
079   9 3/4 Dana Rear Axle 3.54 ratio (Sure Grip) 10" Drum & 7290 Yoke
080   9 3/4 Dana Rear Axle 3.54 ratio (Sure Grip) 11" Drum & 7290 Yoke
081   9 3/4 Dana Rear Axle 4.10 ratio (Sure Grip) 10" Drum & 7290 Yoke
090   7 1/4 Rear Axle 2.76 Ratio (Sure Grip) 10" Drum 1.875 Pinion & 7260 Yoke
100   8 3/4 Rear Axle 3.23 Ratio (Open) 10" Drum 1.375 Pinion & 7290 Yoke


The 3rd member date should have been in white, but I forgot and did it all in the same axle yellow.     But this might help you with what the stamps might look like on your car.

[Shane Kelley]

Is that pick of the 3rd member red oxide? Kind of looks like it might have been but hard to tell.

[Cuda Cody]

When I got the car someone had repainted it black.  I used paint stripper to slowly remove the paint so I could see the numbers stamped on it.  I thought the red was the primer they used under the black.   

Is that pick of the 3rd member red oxide? Kind of looks like it might have been but hard to tell.

[anlauto]

  It looks like the markings were under the red

[Shane Kelley]

It looks like the markings were under the red

I believe you may be right! I'm still curious about that anomaly.

[anlauto]

I think it's a case of a warranty part. Painted red oxide for the purpose of long lasting shelf life.
It's like upper control arms. On Hamtramck E Bodies, assembly line parts were never painted black, they were simply bare steel. But over the counter replacement parts were painted black and stamped with a part number for longevity sitting on a shelf.

[pink aar]

Thanks Cody for the info.

[BillyB]

@Cuda Cody

Any idea if AAR / T/As used a 10 or 29 tooth pinion spline? I will need to build a 489 3rd member assembly because my T/A has a non-original 741 sure-grip 3.91 setup which also needs rebuilt, so I thought I would just do it up right to be correct for a T/A since I'm going to do it anyways. I will also need to change out the propeller shaft to the proper 7290 large yoke in the back.

No build sheet, so I'm going to have to choose between 3.55 or 3.91 gears. Any advice? I'm leaning to 3.91s for a stoplight car. I don't think I'll be doing much highway cruising with it.

Thanks in advance.