8.25 chrysler

[flyinbrick68]

How much abuse will an 8.25 rear take. Will it hold up behind a big block as long as a guy is somewhat decent to it?

 

[Davea Lux]

The 8.25 was a pretty good rear end behind a 6cyl, 318 or 360 2BBL. When you start talking about a big block, the 8.25 will probably break because it was not designed for the amount of torque available with the larger engines. If you have a big block, any time you put your foot into it you are running the risk of a major breakage incident. It is very difficult to drive a big block and not sometimes give it some foot.

Dave

 

[Snotty]

Just for discussion, what are you thinking of running, and in what vehicle?

 

[flyinbrick68]

It's the stock diff in my 72 fury as far as i know. The 400 is going to get replaced with a mild 451 this year. Most likely won't make over 450hp at the crank with the parts i have so nothing to radical.

 

[Davea Lux]

It's the stock diff in my 72 fury as far as i know. The 400 is going to get replaced with a mild 451 this year. Most likely won't make over 450hp at the crank with the parts i have so nothing to radical.

'72 fury with a 400 should have an 8.75 rear end. If the rear end is a 3rd member type it is an 8.75. If it has a bolt on rear cover, it is probably an 8.25 but there was also an optional 9.25 available.

Dave

 

[Snotty]

I had the 8.25 in the '79 Cordoba I owned, 360, 4bbl. When I got it it had three teeth gone on one of the spider gears. Instead of fixing it, I replaced it with another one out of a '77 or 8 Fury, only it had Sure Grip!!

While getting some grease and a few other things, I asked the salesman, "What would an 80 year old woman have to do to rip three teeth off her spider gears?" I'll always remember his answer: "Did that Grandma have a teenaged grandson?" Ha!!

 

[furious70]

Depends on how you drive it. 8.25 would live behind that 451 if you just putz around on Sundays. You break stuff when you have great traction or you have the tires spinning and suddenly grab traction.

 

[flyinbrick68]

Wander if its been swapped at one point in time.... hmmm

 

[flyinbrick68]

Is there a section of the car that tells you what rear axle you have?

 

[Davea Lux]

Is there a section of the car that tells you what rear axle you have?

Look at your build sheet, the type of rear end is coded. I also sent you the photo ID earlier.

Dave

 

[The Goose]

Is this the C clip one that lets the axle slide out when you put slicks on it and take it to the track?

 

[Davea Lux]

Is this the C clip one that lets the axle slide out when you put slicks on it and take it to the track?

No body in their right mind takes an 8.25 to the track, but yes it is a c-clip style unit. All that holds these axles in is the clip and if it breaks, goodby axle and rear quarter panel.

Dave

 

[flyinbrick68]

Look at your build sheet, the type of rear end is coded. I also sent you the photo ID earlier.

Dave

Thanks dave looks like i need to find an 8 3/4 then. No idea where a build or broadcast sheet would be on it.

 

[Davea Lux]

Thanks dave looks like i need to find an 8 3/4 then. No idea where a build or broadcast sheet would be on it.

On that year car, it will usually be on the top half of the rear seat on the inside.

Dave

 

[The Goose]

No body in their right mind takes an 8.25 to the track, but yes it is a c-clip style unit. All that holds these axles in is the clip and if it breaks, goodby axle and rear quarter panel.

Dave

I seen it more than once at Firebird in the 80’s. Run whatcha bring Lol!!!

If you’re lucky it doesn’t take the quarter panel with when it exits stage left. Thanks bud. Figured you’d know.

 

[Davea Lux]

I seen it more than once at Firebird in the 80’s. Run whatcha bring Lol!!!

If you’re lucky it doesn’t take the quarter panel with when it exits stage left. Thanks bud. Figured you’d know.

GM had an issue with their 10 bolt rear ends doing that. In 1971 the state of Oregon bought a fleet of 454 Chev Caprice cruisers with that rear end. I don't know what idiot spec'd that instead of the more reliable 12 bolt unit, but it was a disaster. Patrol officers would stand on the throttle from a standing stop to chase a speeder and lose the axle. They also lost a bunch of rear ends with the carrier bolts breaking and trying to spit the ring gear out the rear of the case. Unit was just to light. Oregon sued GM but I think they lost.

Dave

 

[flyinbrick68]

It's definitely dirty but this should be an 8 1/4 rear correct?

 

[furious70]

Yes

 

[flyinbrick68]

Yes

A guy local to me has a 72 fury with a 9 1/4 is that worth looking into over the 8 1/4 chrysler strength and durability wise?

 

[furious70]

substantially stronger. If it's the right width and perch set up and a gear ratio you want it could be a deal.