few t-cases have offset rear outputs like the Cruisers....which limits your options for gearing and axles. Getting into the "big" HD stuff usually means either running a centered rear diff or getting one custom made...and custom = more $$$ plus tougher-to-find replacement parts.
the BEST way is to keep the rear diff pinion in line with the t-case output. There are people who run a centered diff with offset t-case, and a centered t-case with offset diff. The "experts" say it can be done, but the compound angles are tougher on driveline components. They should at least be "close" to inline.
I do know of people who have done it in stages...installing 60 axles with the rear centered then doing the centered t-case later.
If you are looking for a full floater Dana 60 rear, 35 spline will be hard to find, most are 30 spline and less than 1.5 in dia. You can however find some rear Dana 60s that were offset some, I am told usually on vans.
Another option would be a 14 bolt. It is considered a centered diff, but the pinion is offset some, and one axle is shorter than the other. It's only a couple of inches but may be worth a look at as the axles are 1.5 30 spline. You also can find 14 bolt cab and chassis rea ends which have a narrower WMS to WMS at about 63" and better suited to cruiser width (unless full width is what you are looking for)
[quote author=rusmannx link=board=1;threadid=4879;start=msg37364#msg37364 date=1062557583]
i would like to take them down to 55 inches (stock 40) wide.
i didn't think about a 12 bolt, but that is a good idea.
what about the front axle?
I actually mentioned 14 bolt, 12 bolt would not be as strong. Custom built to cruiser width axles will take a bit of doing and prolly a lot of $$$. I guess I need a bit more information for why the axle upgrades. Are you planning to go to bigger tires? What type of wheeling do you do? Basically whats your reason?
I think the stock axles are fairly tough when running 35s or smaller. If you wheel hard like I do, maybe put some longfields in the front and call it good. Now if you are talking 38s+ and heavy rock crawling, then you need to look at a Dana 60 front. I see no reason to change the stock front end unless your set on 38s+ or competition use. Some people have looked into Dana 44 front axles to get away from birfs, but with aftermarket birfs available there is no need.
Ah the how big should I go ? Well I personally always try to build in everything I want at the time. At 36-38 tire size your at a grey area....
Stock axles with Longfields will hold up to a lot of abuse, but things do break probably inner front axles with a 38. The rear will take this abouse and the weak link will be the pinion, esp on a SOA.
But over kill would be Dana60 front / 14 bolt rear. But even at 38s you will be draggin a lot of axle around (weight and clearance), shaving would be at the top of my list with a combo like that. It will be very costly, esp considering you want to run at cruiser width.
Its your choice, stock is good with aftermarket upgrade, but the D60/14bolt offers upgrades in tire size without worries.
I personally would just stick with stock, add in some aftermarket birfs and 36s or 38s, and be happy until you start breaking every couple trips out. By that time you'll know what tire size and axles you want, and will probably need a new body and drivetrain to go with it.