i have a 93 f 150 with 3.55 gears limted slip rear if i regear to 4.56 do i have to change carriers and get some new limted slip diff for the back

 

No you don't.

 

everywhere i look to buy gears say i need a 3.91 and up carrier why is this if i dont have to change the carrier

 

When I had 4:56 gears installed, I needed to change the front carrier. They told me that on the Dana 44 the carrier needed to be replaced as well. I think they told me that the tallest you can go without a carrier change in 3:73. Don't quote me on that, it's been a while.

Hoped this helped.

 

On the D44 front axle a carrier change is necessary to go above 3.73, but not on the 8.8 rear axle.

 

When you put a 456 in a 8.8 .. I think you need a different pin .. for clearence for the 456 ...

 

I think thats how it went. It's been a few years since I had them done and I gave the truck and the reciepts to my son.

I am certain the front carrier needed to be replaced, and I don't think anything was needed on the rear except gears and the install kit.

I'll try to get ahold of my son an see if he still has the reciepts to verify.

 

i just did it you don't need a different pin, you need to notch the ring gear by the hole for the pin so you can slide it in, you will need a 3.91 up carrier for the front diff. i need to do the change on the front still so i'm not sure if i need to notch the gear for the pin in the front

 

What he said ^^^^

 

I have heard about grinding the ring gear to get the pin to fit.Everone has a different way to do it..I dont like grinding on a ring gear tooth when you can get a notched pin for $40 bucks..But most pepole upgrade there carriers when they go to a 456 then you dont need the pin ....Lew

 

With the 8.8 the pin is a MUCH bigger weakness then the gear, A gear ground right won't cause any problems, but ANY weakness in the pin will.

 

...Sounds interesting..I have never done that or used the noched pin..I run a 8.8 with a eaton truetrac 456 gears & superior axels...Works good for me..Lew

 

the notched pin scares me because if one of your axles breaks that pin and the c-clip falls out your pretty much screwed, the pinion doesn't even ride where you notch the gear so it's all good :-)

i ditched my detroit lockers when i did the change, kind stupid but i had good reasons