I'm looking into regearing my 3.55s up to 4.88s or 5.13s. I can get new gears for the rear for around $200. The site I was looking at didn't say anything about the front end though. I have an 8.8 in the rear, so does that mean I have the same in the front? I saw a post somewhere on here that said all the fronts are 9.75 regardless of what's in the back. Is this true?
Also somebody told me that I can only fit like 4.10s on my stock carrier, yet I haven't read anything about needing a new carrier to go bigger than that. I just need a little guidance.

 

you dont need a new carrier up to 4.88, after that i would need to make a phone call, all f-150 4x4 hav a 8.8 in the front regardless of the rear, it is a ifs 8.8 reversed cut gearing. you will need to do a gear change to the front and rear at the same time. also what size tire do you plan on using? 5.13 is a pretty low gear i have 38" and 4.88 got me into the correct RPM range. let me know if you need any more info

 

I thought that 5.13s seemed pretty low but I was just refering to one of those charts that you see all over the place. I plan on running 35s and possibly 37s eventually. If I were to buy 4.88s would I just buy 2 of the same thing or are they different products? Also I have a 4.6l so I'm trying to make up the power that my engine lacks with lower gears. I have rebuilt 2 rear differentials, but I've never opened my front. It looks a little different. Is it harder or is there any major differences I should know about?

 

4:88's would def. be fine IMO.

 

the rear uses a standard 8.8 the front uses a 8.8 IFS with reverse cut gears, what do you mean you have rebuilt rears ends before? doing a ring and pinion requires some speceal tools like a bearing press and a magnetic base dial indicator, if you dont feel comfertable doing it yourself i would find a freind who is or take it to a driveline shop. doing the front is the same as doing the rear, taking apart the axles is a little diffrent but the setup of the ring and pinion is the same. good luck

 

I have replaced the stock open rearends with posi units in both of the trucks that I have owned. I called up Randy's Ring and Pinion, which is who I have always bought my stuff from, and he told me not to go lower than 4.56s. He also said that the front differential with IFS is a completely different setup than the rear. He told me that I should probably not attempt the front. So now I'm getting different opinions and I'm becoming more confused than I was before I asked the question.
I do feel comfortable working on a REAR diff, but I have never opened up a front so I need to know if there are any major differences. If it is just about the same then I should have no problem.

 

Randys is a good source, when you put in the posi units did you check the backlash and your run pattern ( grease paint on the gears to see the setup pattern) if you set it up properly, than you should have no problem seting up a ring and pinion. and doing the ring and pinion in the front is exactly the same setup as the rear, like i said earlier if you dont feel comfortable doing in take it to a shop or find a freind, it is easy to mess up the setup of a ring and pinion, one time i spent 8 hours pulling the pinion of and ajusting the pinion depth before i got a setup pattern i was happy with, this was on a dana 60, but setup on a ring and pinion is close to the same on most axles. good luck

 

Yeah I made sure everything was within specs on my posi. I was surprised because it really wasn't as hard as I thought it would be. Both times it took me around 2 hours to shim it out correctly and check the wear patterns. I'll have to do a little more research but so far I think I'll probably end up doing it myself.

 

it really isnt that hard to do if you know what you are doing, have have done over 15 in many diffrent vehicles nver came across any problems exept with a dana 60 that we had to use a case spreader to get the carreir to fit, other than that i have never really had any problems. and with the 8.8 you dont even need to replase the carrier so setup usally goes smother, good luck