I currently have a 9.75 open diff and I found a 8.8 with a limited slip in the junkyard. My question is....will the 8.8 complete rear axle bolt in place of the 9.75 that I currently have? Just making sure all of the mounting points are the same and the drive shaft and such....

barry

 

what year is your 9.75 ?

what year is the 8.8 ?

And thats like going from a Dana 60 down to a dana 44 to put it in perspective. The 9.75 is becoming more and more a hot item. Its basically the size of a Dana 60. I'd keep it. If you don't want it, where are you located ? I might !

 

I agree, the 9.75 is a way better axle. It would probably be cheeper anyway to convert the 9.75 to a LS than it would be to get a complete axle from a wrecker would it not?

 

X2 to what's already said. I would investigate a LS or locker carrier for your 9.75 before I'd ever consider a 8.8. Matter of fact, I'd probably keep a plain 9.75 before a LS 8.8.

 

I have ran 8.8's in the past with no issues. I have had them in GEN 1 Lightings, and all of my Mustangs with no issue. I am not pulling anything real heavy, that's why I thought the 8.8 would be fine. I can swap complete axle with the local yard for about $250. I would guess it would cost me alot more than that to put a limited slip in mine, plus mine is a 3.31 and the 8.8 is a 3.73. Well I am not sure what to do now....

My 9.75 is in a 2000 F150 and the 8.8 is in the same body style truck. not sure of the year, but 99-03 range.

barry

 

Yea thats cheaper than putting a LS or locker in your 9.75. Its your truck if thats what you want go for it. Another question i have is is your truck 4x4 or 4x2? if its 4x4 the lower gear ratio in the 8.8 will cause a problem, you would have to change the front diff gears to mach the 373's in the rear.

 

Not down playing the 8.8 at all, just wanted to make sure you knew what was up. Heck, I run the 8.8 in my truck as is. Looking to swap up to the 9.75, but to each his own. I do tow often, and abuse the heck out of my truck. Just waiting for that little rear end to give it up.

 

Mine is a 2wd. Mostly back and forth to work, however I am doing some major landscaping at my house and am hauling up to 4000 pounds of rock, but that is not an everyday thing. It may happen 8-10 times this year and then I am done. I have a mustang that I dump way to much money into....

Barry

 

sounds like the 8.8 would work for you. Lower gears and LS for $250 ? Not bad at all if you ask me. Lifted at all ? larger tires ?

Sounds like it would be a direct swap. You have rear disc ? does the 8.8 ?

 

Stock ride height...I do have to make sure the 8.8 has disc rears. I have disc and that is one thing I would like to keep. Providing it does, will all other things bolt up? What about the drive shaft?

Barry

 

everything should bolt right up. Pretty sure the driveshaft will too. Worse comes to worse, you can bring the driveshaft to a driveline specialist, have them cut the end that bolt to the diff, and have them weld on the correct flange. I really don't think that will be necessary. Maybe you can pull the driveshaft with the 8.8, just to be sure you have it, just in case.

 

Do a search for when folks go from an 8.8 to the 9.75... I think they say that they have to shorten the drive shaft a couple of inches. So, if you went from the 9.75 to the 8.8, you would need to lengthen the drive shaft.. Unless you can also get the drive shaft that comes with the 8.8?? You'd want to swap out the U joints anyway, so you could still use your original output shaft from the trans..

Just a thought and what I recall 'hearing' about in past messages...

Good luck!

Mitch

 

I think I can get the drive shaft too, so I'll grab it if I do this.

Barry

 

i have found drive shaft length comes into play swapping from fleetside trucks to flare side trucks built my 99 Flare from the ground up. Bought it with a ruined from. Fleet side trucks have a shorter drive shaft. so u might be getting a drive shaft built too and add that to the cost