rearend ID

I have a 72 Skylark conv. with a 2:56 posi. I want to change to 3:73 but there is no stamping on the rearend axle tubes. How else can I ID what rear I have?(8.2 or 8.5)o No: It is a 10 bolt.
Don

 

8.5 Has two square ears around 5 and 7 o clock and cover at 3 and 9 o clock has curves in. if its the stock rear its 8.5

 

Lonnie, thanks for the reply. Like this? its kind of like ears.

 

That's an 8.5 great rear end bolt in axles. get in contact with monzaz on this board. hell of a guy and a rear end guru. i will never buy rear end parts from anyone else. And be careful going from 256 to 373s i floated the valves a few times when i did the swap. it was like driving a totally new car

 

Quicker, I would hope? It is kind of a snail from a start now. I plan on a 200-4r swap at the same time. Just getting ready.
The engine has a mild cam, some head porting, and a 1800-2000 converter. Will get together with Ken about a quadrajet rebuild, too.
Thanks for the help.
Don

 

Care to enlighten on the how and why the valves floated.

 

too many rpms too fast. This happens with Hydralic lifters...Solid lifter cam tappets do not require the pump up from the oil pressure. Jim

JD

 

I see. That makes sense.
Jim , what about a complete set-up to switch the rearend over to 3:73's? Do you sell that stuff? I would want quieter gears like the originals, I heard that Superior( I think) makes some. Should the axles be checked or rebearinged?
Thoughts?
Thanks, Don

 

rate of acceleration changed. plus i spun the tires real bad and it rev so fast. i just wasn't used to it

 

By the way. all gears should be quiet if they're new. check out Jims website. you should find plenty of stuff.

 

Lonnie, what did you do with your 2.56's?

 

out back in the shed. attached to an open carrier

 

I'm thinking of switching to a set of 2.56's. I'm not sure if they would work in a 3 series carrier though. I've got a few other things to take care of first. Maybe in a month or so I might be game if your interested...

 

nope not on a 3 series... but, just let me know. dont forget to remind me.

 

Sounds good to me. I'll try to remember...(That's like a blind man walking down the rim trail at the Grand Canyon!) ou:

 

Ya know, now that I'm thinking about it, I'd bet that my Skylark has a 7.5 rear since it was a 6cyl! How can I tell for sure?

 

7.5 ears look like someone drilled the corners off an 8.5 at 5 and 7 clock

 

Thanks! I'll check it out either today or tomorrow when I'm under it replacing a u-joint.

 

That's exactly what it looks like. So I guess that means your set up diffidently won't work in the Skylark. Bummer.