To go through all of the effort to go solid axle and then to swap in a D44 sounds kinda like a waste to me. A D44 and a D30 use the same diameter axles, the 44 just gets bigger tubes and the bigger R&P (and here's a hint, the R&P on the D30 isn't the weak point).

I can destroy a D44 axle shaft on command. 4lo reverse and back up against something that won't move and ::POP:: there it goes.

If you seriously wheel your X and you go D44 you'll be kicing yourself within a year for not going D60.

I know alot of D44 axles can be bought for the price of a 60, but it saves in headaches and downtime.

As for a D70 front, that's just plain old overkill, not so much for the strength but just for the weight factor. A D70 rear weighs about 475 lbs and a front weighs in at about 550. If you're going that far might as well just do rockwells.

Justin