anyone know if there are any 8.25 rear ends that will bolt into my 63 dart without alterations. currently running a 8.75 from 71 a body I want a lighter and less rotating mass with a 4.11 or 4.56 gears

You are looking for a 1973-1976 A-body 8.25" rear end...I think the switch will save 50 lbs, but you won't be able to do a 1 hour rear ratio change at the track to get your mileage back if driving there... Sadly most 8.25" are highway geared at 2.45-2.76 being most common, /6-3speed and most V-8 were 3.21 stock, 3.55 was the option for the last of the 340/360 cars. So if you find one, you will have to plunk for the gears to put it right (if the ratio is 2.45 or lower, you're gutting it anyway since the diff isn't compatible with any ring gear higher...

You might keep your eyes peeled, in this economy, you might check Craigslist for a 'deal', I got my 4.56 sure grip 8 1/4" from a guy that needed to recoup the cost of the A-body Dana he was putting under his 73 duster...$375+ gas and travel time was worth it (I don't think you can get a sure grip unit and less than 100 mile ring and pinion for that price.)

-D.Idiot

Just so you know, switching to an 8-1/4 will not make any noticeable gains.

Also, an 8-1/4 will be large bolt pattern if you haven't already switched it.

_________________
Official Cookie and Mater Tormentor.

I should think that you will also have to shorten and re-balance your drive shaft.

_________________
obliquely-inclined state of mind

Not when going from an 8 3/4" to an 8 1/4"...his yoke should have enough play to allow that to bolt in...but the bolt pattern switch is going to be fun unless he already has late discs up front as D stated.

-D.Idiot

My bad: I skimmed over the fact that he was already running the 8.75".
That's what I get for posting before morning coffee...

_________________
obliquely-inclined state of mind