[Flex]

With any luck I'll be picking up my new BJ74 this weekend. I'm not the kind of guy who can drive a stock truck so it'll be getting lifted almost immediately. Aside from the obvious steering/stability argument is there any reason NOT to spring over? Better flex, more room for tires etc is appealing to me, and I've always sprung over my *cough cough...jeeps..cough* and had great results.
What's the largest kit lift?
What size tires can I run with a kit lift?
What rim backspacing or offset do I need for a 12.50 inch wide tire?
Do I have to lengthen the cables for the lockers after lifting?
Gearing for 35's should be 4.56's or 4.88's?

Sorry for the barrage of questions guys, and thanx for the help!