I have an 03 reg cab 4.6L 4x2 that I tow my rock crawler with. The truck does well for not having a tow package but needs a little more umph.

I read the tag on the 8.8 rear a while back and if I remember right it had 3:00 gears or something close to that.

What year trucks should get me the 3.55 gears I want.

I figure it will be allot cheaper just to hit the scrap yard and pull the rear carrier for a swap than buying new ring and pinion with install kit. I have a programmer to set the speedo right.

Thanks, sorry for the newb question.

 

What is the axle code on the door jamb sticker?

 

You can use any 97-03 axle from a 4.2 or 4.6L truck. Before you start, find out what you have now. No sense is replacing your 3.55 with another one. Look at the driver's door sticker for the Axle Code. Should be one of these:

19 = 3.55 open
H9 = 3.55 LSD
26 = 3.73 open
B6 = 3.73 LSD
27 = 3.31 open
18 = 3.08 open
25 = 4.10 open
B5 = 4.10 LSD

Gears are pretty cheap, though for 2WD. Something like $250 new if you install them yourself.

 

Thanks, that is what I needed to know. The code is 18 on the door sticker.

 

Ouch.

You are better off with a professional gear swap - you don't know what shape the thing is you find in the boneyard. If you tow, I recommend 4.10's, and you will need some kind of tuner to correct the computer whenever you change axle ratios or tire sizes. You could also add a limited slip. The 4.6 thrives on high RPM's so 4.10's are far from extreme.

 

Thanks for the advice. I do have a programmer so fixing the speedo is no big deal. As far as the gears, if I pick up some used ones I will put the dial indicator on and some marking compound to make sure they are still in spec.

 

You will probably not be able to find anything in a 8.8" boneyard axle lower than 3.55. Both my truck (see sig) and my son in law's 98 4.6 ORP have towing packages, and both have 3.55 LS. Please price out a new gearset and compare it to the boneyard price before you pull the trigger.

 

There is a very small percentage of OEM 4.6L's with 3.73 gear (some Supercrews with 17" wheels), but no 4.10 that I also recommend.

 

I did not know they even offered a 4.10 from the factory.

That ratio would be great, but you'll have to pay for an aftermarket set of gears most likely.


I agree with the others, the 3.73 is going to be much harder to find than a 3.55.

IMO, go for a 3.73 LS if you can find it, but a 3.55 transplant would make a noticeable improvement over your 3.08 at minimal cost.

 

4.10 is only available in certain years heavy payload package (7700 GVWR) and only mated to the 5.4L, which has the 10.25" rear end. I suppose it would still work if you're swapping the whole axle. That's going to be even more rare than a 3.73.

 

That will also be a nightmare - 5 lug wheels on the front and 7 lug wheels on the rear.........