Rear Diff question

[MidnightSpecial]

I got a question about the rear in my 1968 Coronet Deluxe.

What was the standard diff to come in these cars?

It seems I have a Dana 35. From what I have been told its not the standard on this year.

What kind of power can this thing take before it grenades?

This is an old picture before I took before I cleaned it up.

 

[monaco66coupe]

Basically a 7 1/4 rear end. standard on the six cylinder cars. and would be in a 68.

 

[MidnightSpecial]

Thank you sir.

Now I know not to waste any money on it. Time for an upgrade!

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so they still put it with the factory V8?

 

[Propwash]

That looks to be a 7 1/4 rear end. Dana 35 is more rounded

 

[monaco66coupe]

usually 8 3/4 in a v8 for 68. However, I had a 69 get the 8 1/4.a cheezy rear end for a B body in my opinion.

 

[bigblock]

I have a factory 318 auto 70 Coronet that came with that axle. Got an 8 3/4 in it now so IDK what abuse the little axle could take. Try it and report back when it grenades!

 

[Meep-Meep]

Sure looks like a 7 1/4 to me. Those are standard on /6 cars and I have never seen one in a V8. Even a 318 B body got an 8 1/4. Check your 5th digit VIN code. If C then originally a /6 car.

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For driving around it will hold up fine, but if you ever get traction and apply a large amount of torque to it you better get some kitty litter, a dust pan and broom.

 

[MidnightSpecial]

Sure looks like a 7 1/4 to me. Those are standard on /6 cars and I have never seen one in a V8. Even a 318 B body got an 8 1/4. Check your 5th digit VIN code. If C then originally a /6 car.

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For driving around it will hold up fine, but if you ever get traction and apply a large amount of torque to it you better get some kitty litter, a dust pan and broom.

its a d code car. Someone may have taken the factory one a long time ago.

 

[cdr]

that would be a 273 v8

 

[MidnightSpecial]

that would be a 273 v8

Yeah thats what I have in the car. Numbers matching engine. Thats why i find it odd i have this rearend. But like I said it probably was yanked a long time ago.

 

[Cranky]

The 273 is by no means a torque monster making 260 vs the /6 @ 215 ft lbs so the 7 1/4 will do the job. The 273 is only about 50 lbs heavier than the 6. If your car came without any options like AC, PS etc, then the smaller rear was probably the one.

 

[MidnightSpecial]

The 273 is by no means a torque monster making 260 vs the /6 @ 215 ft lbs so the 7 1/4 will do the job. The 273 is only about 50 lbs heavier than the 6. If your car came without any options like AC, PS etc, then the smaller rear was probably the one.

It's a factory A/C as well. Just seems like an odd bird haha.

Thanks for the info Cranky.

 

[Meep-Meep]

I'll agree with Cranky that it could have very well come with a 7 1/4". This leads to anther question when the 8 1/4" came out. My 318 69 Charger had an 8 1/4", and I know 68 was the last year for the 273, so perhaps 69 was a big transition year in the small power train dept.

 

[monaco66coupe]

The 1968 Chrysler parts book shows the 273 and 7 1/4 available, also the last year for the 273 in a B body. 69' the choice was slant six and 7 1/4, or 318 with the 8 1/4. you could order the 8 3/4. I liked my 273 in the 67' I had. In 67 I also had the 727 and 8 3/4, and it was just a belvedere two. I miss that car, the GTX is fun, but the 273 was my first 67'.
I saw 18 city mpg all the time. More poop than the slant, not much difference in power from the 318.

 

[Mr Belvedere 30144]

If you are going up in power but not crazy you can get an 8 3/4 741 sure grip fairly cheap and it will hold up fine. I have this rear in Mr Belvedere and I am running 450 HP 490lbs of torque. Just my opinion.

 

[tallhair]

If you are going up in power but not crazy you can get an 8 3/4 741 sure grip fairly cheap and it will hold up fine. I have this rear in Mr Belvedere and I am running 450 HP 490lbs of torque. Just my opinion.

This is what I'd do when the opportunity presents itself or work is needed on the one you have. No rush if it's holding up but keep an eye out for a complete 8 3/4 set up thats local and affordable either SG or Open.

You can run an open 2.76 - 2.94 - 3.23 until a SG chunk presents itself too.