8.25 rear pros

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homeboysduster

homeboysduster

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OK So as to survive the bashing yes I have searched the forum and have read lots about the 8.25. With that being said I want to use a 8.25 behind my 5.7 hemi/518 trans. I have found a detroit truetrac, mosier axles, and a disk brake conversion kit. So most of the threads I have read spend a lot of time ether bashing the rear or praising it. Yet I don't see any reasons for the cons or the pros. So I guess I am asking what are the reasons for it's strengths and the reasons for it's weaknesses? What makes this rear strong and what makes it weak?
 
Its a great rear with HP limitations. Much also depends on your level of traction. If your making 600 hp but not putting it down, its your tires that will suffer.
Personally I wouldnt go much over 400 with an 8.25 Also, if your going to spend that kind of money it would be much better spent to upgrade.
Its a good rear in my opinion. I have ran one behind a stout 340 and never had any problems.
 
Thou the 8 1/4" is capable, I believe the increased use of it is mainly because the 8 3/4" is getting harder to find and has the smaller bolt pattern, 5 on 4" instead of the more common 5 on 4 1/2". Yes it will handle a fair amount of HP, keep in mind the ring gear is only 8.25 in diameter. The axles are 27 spline and are kinda puny. Yes they will handle most street cars that are daily drivers. And if used with that in mind they will fill the bill. I have a 3.21 SG 8 1/4" under my 360 69 Dart for the last 12 years and have not had a single problem. If you plan on bolting slicks on your car and plan on 1.30 60 ft'ers than this is not the rear end for you. All this is MY opinion, I'n sure some will not agree.
 
Pro it's better then a 7 1/2
Pro parts are pretty easy to come by
Pro it's an easy swap
Pro 4.5" bolt partern
Con it's only 8 1/2"
I have a stock 8 1/2" with a 3:55 suregrip an auto and 330 hp 340. I've had no issues. I'm am soon to install a 408 with about 400 hp and I believe it should be fine, but it's mainly street driven. If you have a mannual trans, or you plan on doing some hard launching you're definitely pushing it!
 
I used one behind a 360/425hp stock car 3600lbs.with 11in tires ,the axles are very good I never lost or had a broken axle on dirt with outstanding traction on sticky tracks or spinning the tires when wet hitting the ruts in the track when racing last were 10 " deep in the turns while the bowtie boy were snapping axles in 10 and 12 bolts rears and when there was a LITTLE rubbing I never lost, a few gm snapped their axles and I ran the stock posi unit with a 4.56 gear.
 
Thanks guys! Just to set the record right I have been apart of this forum for a long time. I love a great Duster or a 60's barracuda!! But my current project is a dodge ram with a 5.7 hemi and a 518 auto trans! Now I know your wondering why on earth would you use a 8.25 rear in a full size truck! Well I have been looking for a 9.25 rear from a dakota and have found nothing! Bad part is it is the same rear as my truck!! The reason for the swap is the Dakota rear is 6 inches narrower than mine. Letting me install wider tire. I know A bodies have been using the 8.25 for a long time! I know if I could get the info I want this is the place! The 8.25 is a lot more popular than the 9.25. hence my looking into the 8.25!
 
Now that you say it is going in a full size pickup, the cons have another point. If you ever want to tow or haul heavy loads with that truck, the axle bearings are not sized for those loads. Sure you may get by, but they would fail if pushed. There is reason Dodge never put them in full size pickups.
 
I have a 1987 D100 long bed that came from the factory with an 8 1/4.

225 4 speed manual OD.
 
Well I read in the Hemmings motor news that the rear was installed into everything from a duster the a w400!!! I was amazed! Also the rear is a staple for the jeep guys too. So it got me to thinking about just using the rear so I can get the look I am looking for. This truck will never tow a thing! It is a street truck that will be for going fast and looking good while doing it!!!LOL I look to install a Detroit trutrac diff and a set of mosier axles with a disk brake conversion kit. I think that will do the trick! What you guys think?!
 
in the 80's the standard gear for 1/2 and light 3/4 ton pick ups and vans was the 8 1/4" gear
 
A big plus is just about everything you could think of is available for them, and a lot cheaper that for most other rears due to their widespread applications.

Just about the only thing I don't like about them is that they use the axle as a wheel bearing surface.
So lets say you loose a bearing surface on an axle.
You go out and get the repair bearing kit (cheap enough) and the bearing kit relocates the bearing to another spot on the axle.
When that surface goes, it's axle replacement time.

I know that going in, and am still going to build one for my daily driver Dart with the 5.9 and A500.
Mine will come out of a Grand Cherokee with disc brakes already on it, and will be cut down.
 
Sorry, I stand corrected. I had only seen 8.75, 9.25, and Dana 60 axles.
 
3406pk said:
Now that you say it is going in a full size pickup, the cons have another point. If you ever want to tow or haul heavy loads with that truck, the axle bearings are not sized for those loads. Sure you may get by, but they would fail if pushed. There is reason Dodge never put them in full size pickups.
Click to expand...

Dodge used them in many 1/2 ton pick up trucks in the 80's
 
Here ismy truck!!!!

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26219561_1569406086474108_7251751022558427720_n.jpg
 
I've also seen 8 1/4 in 400 powered Cordobas
 
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