Ok, would anyone know the difference in weight between the 8.25 and
8.75 rears?? I know the 8.75's are a little on the heavy side and know
that an 8.75 could stay with the car through out my engine modding
process, meaning basically I could slap an 8.75 in it and forget about it.
But How strong can an 8.25 rear end be?? Worth swapping in??
The 8.25 rear end swap would be the cheaper setup to do, but not if
I have to pull it out later and replace it. It's alot cheaper to do things
right the first time! opinions please! I assume I could build up the 8.25
rear nicely???

The big advantage of the 8 3/4 is the ease of swapping gears. My 9 year old and I can do it in under a half an hour. I normally run 3.23's but I put in the 3.91's for racing.

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Apparently, the 8.25" is only 10 lbs lighter than an 8.75" - really not worth it if you have access to an 8.75, a much better axle. The 8.75" is actually very strong for its weight.

You might consider a Ford 8" out of a 70s Maverick. This is really a bolt in and you don't even need to shorten your driveshaft. It's about 35-40lbs lighter than an 8.75".

Search "ford 8" on this site and you'll get some of my previous posts.

Lou

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Home of Slant6-powered fun machines since 1988

Although I have the 8.25 under my current duster, and have another one I'm about to run in another car you have to make the decision based on:

Price and Availability (both are getting kind of rare as bolt in rears go)
Initial investment in the 8.75 looks expensive (axle plus say two pigs- one for mileage gearing and one for drag gearing), but you can choose how you want to drive it in an hours worth of swap...
Durability: the 8 3/4 has it hands down, plus you don't have to worry about having a 'c' clip on an axle shaft take a hike during lots of hard cornering. But for daily driving and handling more horses the 8.25 isn't bad


good luck,

-D.Idiot

hmmmmm...
how much crazy, God aweful, painful, expensive work is involved in swappin a 7.25 for an 8.25 or 8.75? (can't seem to find one of those pesky 7.25 sure grips )

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My Dart
GO VOLS!
It's not rocket science, we're just splitting atoms.

For the 8 1/4 it's almost a bolt in if you get one from another A body. You will have to have the driveshaft shortened though.

For the 8 3/4, since you will likely have to use one from another body style, there is more work and expense involved. But it is a very common upgrade.

You will likely need to have the housing shortened and get the corresponding axles.

The spring perches will need to be moved to fit the A body.

You'll also have to shorten the driveshaft with this option.

There are several shops that shorten housings and sell axles to whatever length you need.

For all the work and parts involved you are probably looking at an easy $500 if you go with the 8 3/4 option and have all the work done.

Keep your eyes open. 8 1/4 rear ends turn up occasionally if you're looking for a quick, easy swap. The Ford 8 inch mentioned by Lou is another good option and would involve about the same amount of work as the 8 1/4. They are also more common. Just make sure you check your measurements.

Good luck.

_________________
Rob

I’m Mater
The Kentucky Poser

thank you and good luck to you over seas...

_________________
My Dart
GO VOLS!
It's not rocket science, we're just splitting atoms.

For the 8 1/4 it will be a direct bolt-in if the donor vehicle is slant powered with same tranny as your vehicle, has same wheel base, and is an A body of course. If I'm not mistaken Darts have a 111 inch wheel base while Demons, Valiants, Dart Sports, Scamps, early Cudas and Dusters have a 108 inch wheel base.

Hope this helps.

Dart68