The 7 1/4" with the sure grip would hold up just fine, the 8 1/4" would be better if it had a set of C-clip eliminators available to it (maybe Mosers or Strange carries these nowadays). I've never had a stock 8 1/4" come apart on me in spirited driving or drag racing, but then again I've never done a "bullitt" around the corner or put it hard through the slaloms either. I'd just be a bit concerned about side loading a set of 40 year old axle shafts held in place by a hardened .125" C-Clip.

-D.Idiot

Well, unfortunately some Google searching tells me that c-clip eliminators might not exist for the 8.25" rear, and if they do, they are way too expensive for my budget. Did I mention this is a LeMons car?

My 7.25" is also not a sure-grip. So I guess my questions really boil down to this:

1. Between a 30+ year old, non-SG 7.25" or a 30+ year old, non-SG 8.25", which would you expect to last longer in a road race, where the car is driven hard with stiff suspension but not a lot of power is put down?

2. Is it more or less of a hassle to rebuild an 8.25" unit, compared to the 7.25"? I will almost certainly be changing the gear set no matter which unit I use. I may also try to install a master rebuild kit if I have the room in the LeMons budget.

I would also ask about the availability of replacement gears, but it appears that I can get the gears I want for either unit at about the same price:
http://www.gearsareus.com/gearstuff/gearsmopar.htm

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

The 8.25" would last longer stock against stock, and at least parts are available...(if you are looking for a 3.55/3.91" ring gear and pinion on the cheap...try your local junkyard and a 90's 4 or 6 cylinder Dodge Dakota...)

The 8.25" is easier to work with in many respects, if I had to pick between the two, and it's easier to find parts in the junkyard than the 7.25" in this area.

-D.Idiot

I did a little more searching on the procedure for changing gears, and now I'm wondering if it might be beyond my capability. Unfortunately, the local shop I called wants $300 for labor, assuming I supply the gears and the rebuild kit.

How easy is it to screw up a ring and pinion installation? Is this the kind of thing I shouldn't try to learn by doing?

The good news is that it's only $65 to have the driveshaft shortened.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

I second this. These days, with the amount of effort and cost required to swap in an 8 1/4 rear axle and the effort in changing gears, swapping in an Explorer or other later model vehicle rear axle is often cheaper and the same or less amount of work. If I had known better than I did at the time, I would have gone with a Ford rear axle in my brother's Duster. But, c'est la vie.

The Ford 8.8 also needs C clip eliminators. It also needs one side cut and shorten and a new axle for that side. Along with all the mounting brackets cut off and new ones welded on.

C clip eliminators for 8.25 may be available at 4x4 shops, since they also came in Jeeps. Personally, I don't think you need to worry about it.

The 8.25 would be a better choice snd easier to work with than the 7.25 if its a really good deal and has the ratio your looking for than go for it. But if it is the wrong ratio then I would consider the ford explorer 8.8. You can gain disk brakes a better gear ratio and a limited slip. They can be had for $150-250 then just shorten one side of the housing it only cost me $150 for the one side to be shortened and then have new leafspring perches installed. You can use another short shaft from the junkyard or new replacement shafts from can behad for $80.

I think a 8.8 would be just fine behind a 300hp slant on a road corse. After all I have seen 500hp mustangs using the 8.8 with out c clip eliminators. The good thing about the disk brake calipers on the back is if the clip does come lose you will trash the brake but it can keep the shaft in place to get you off the track to avoid an accident.

The 8.8 explores had gear ratios any where from 3.55, 3.73, 4.10s.

I don't care how good or available a Ford axle may be, no true Mopar person should ever even consider the possibility of using a non-Mopar axle assembly. I never would.

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See "Online Video", now the internets' LONGEST RUNNING comedy / opinion webshow, at www.loudmouthtim.com !

A statement like that really doesn't make any sense. The car doesn't know what brand rear is in it. In my case, a "A" body 8 3/4 rear is just too expensive for my budget. A 8 inch Ford rear is much more affordable, and will fit with a minimum of mods. It is plenty strong enough for my slant engines. I feel unless you are restoring to show the car, use whatever gives the most cost/performance results. Whether it is a rear, brakes, ignition, etc.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Charlie's correct, the end user needs options to arrive at what he wants...Technically even the pro's back in the day swapped to other brand parts in their cars, I seem to remember an article where Sox and Martin fessed up that they didn't keep an A-833 as the 4 speed of choice in their competition cars and went with a Muncie close ratio at one point.

Don't feed the trolls, but maybe I will mention quietly that companies other than Chrysler also used Dana axles and that Australian A bodies didn't get Chrysler axles at all. It's not like an axle assembly changes any essential characteristics of the car.

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Joshua