LCA width/location ?

stock dana 30 LCA mounts are about 30" apart from each other..

Can this number change on a new axle build? For instance, I'm building a Superduty 60, to put the LCA brackets in spots that work, they'll be about 34" spread apart...

If this makes any sense, Will I run into any problems?

It will be fine, mine are touching the knuckles on my full width 60

Nope. Put them where you need/want them. Just make sure your tires don't rub (slight bends can help here) and if you need a certain amount of triangulation for some reason you need to watch that..... But mostly put the where you please.

One piece of advice, put your lower mounts behind the axle tube if you can. In other words try to keep them up, instead of hanging off the bottom like a Dana 30. The less hanging down, the better

also get angled mounts so your joints arnt maxed out