This is a common question among XJ/MJ owners who want to "go big". I've done a lot of research, crunched a lot of number, and here is what I'd say to do (personal opinion).

First and formost it really depends on what size tires you want to run. With that being said I'm going to say it's better to build the D30 up. Here is why;

1) It's bolt in. With a D44 nothing is bolt in. DO NOT, and I will resay it again, DO NOT buy a TJ D44 and bolt it in. It's not a true D44 and you'll really get no benefits. The JK D44 out of a new Wrangler is looking like a good option. It won't take a ton of work to get it in, however you have a different bolt pattern, and it is 4" wider. So now you really need to swap out the rear axle as well. Another option is the Waggy D44. It will take more work to get it in. It is very close to the same WMS, but your now running a different bolt pattern front to rear. This can be solved by either swapping out a different rear axle, or running adaptors. I can't say I'd be prone to running different bolt pattern rims front to rear; especially if you do any amount of wheeling. So stay with the D30 in the front unless your willing to tackle other things.

2) Money spent on getting the D44 under the front can be spent on upgrade on the D30. For the money you've got in setting up the D44 in the front, you can upgrade to alloy shafts and stronger joints. Most likely your going to re-gear the D44 to match the rear anyways (9 times out of 10 they won't match), so the cost of re-gearing is a wash.

3) I have to disagree with Brendan that options are not their for the D30 when it comes to lockers and gear ratio's. I'd venture to say that the D30 is one of the most supported axle's when it comes from the aftermarket manufactures. You have MANY options when it comes to lockers, and MANY options when it comes to gear ratio's. The D30 is supported for a tire upto at least 38" when it comes to gears. I'd venture to say anything larger than that your not going to be driving it on the street anyways so why does it matter?

4) Give me $1000 for a front axle. I think the end result will be a stronger D30 than you could have a stronger D44. Just my opinion though...

5) You swap a D44 into the front, most likely your going to need to adress the rear axle for one reason or another. Width, Gears, Etc.








 And yes I've had a D44 ready to build for the front and sold it to build up a D30 instead. Once again though, it really depends on what size tire your going to run and what your using your Jeep for. What works best for me may not work best for you.