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I am going to buy new tires for my cj. I have the dana 30 in the front and amc 20 in the rear. Both have detriot lockers and chromoly axle shafts. Can this setup handle 36" swampers?
Well it depends on how you wheel it. Depends how much of a lead foot you have and what type of terrain is key. I have had great success with just running both the Dana 30 and AMC 20 (rear is locked), I do not have my front locked and run stock axles, but it is very common to break a front axle with 35's or 36's from what I have read and heard. I run boggers on trails and rocks which grab alot more than the TSL's.
Far from being an expert, but over and over again I keep hearing don't exceed 33" to be on the safe side with stock axles.
Me and my buddies have yet to break anything. They all run stock 30 fronts, 35's and 258's, however 2 have a 44 rear and one has a 20 rear with 1pc axles. I still run a stock front, and 2pc. axles in the rear and have yet to have any problems with 33's. However now that I welded the rear I'm sure an axle will strip the next time out. I wouldn't say we are hard on our rigs, but we aren't *****footing around either. It's really up to how you drive.
I think with the upgraded shafts 35s would be ok depending on how you drive and over what terrain. 36 is starting to push it IMO.
Too many variables. If all you're doing is daily driving with some ocassional light trail use and a light pedal, they should be fine. However....

The Dana 30 is gonna grenade if you start doing any sort of gonzo wheel spin. Especially with the locker. Personally, and it's JMO, I wouldn't run anything larger than a 33"-35" tire with the OEM axles. Even with upgrades. And keep the wheel spin to a minimum.

I ya Go larger...Go Big. 60/60, 60/9" or 60/14blt. 'Cause if you're thinking about running 36"...You're gonna end up with 39's.
Ditto what Hack said...........if it's strictly street driven 36's should be fine as long as you aren't hot rodding it. However on the trail a light right foot is gonna be your best friend.

Of note, I run 33's on my D30/AMC20 w/1 pc Superior Rear Axles and have no problems.
36s and D30 on the street would be okay. 36s and D30 on the trail is a recipe for breakage. It sucks to be "that guy" on the trail... broken, sweating like a pig changing axles while everyone else takes the time to eat their lunch and watch.

I've seen a few D30s break alloys shafts with 35s and Moderate wheeling. I've seen a stock D44 break a shaft with 36s and Moderate wheeling.
Keep off the throttle, cause you can break that 30 real fast when it gets turning then finds traction all of sudden. Or just bring extra parts, thats what I do. Juck yard axles are cheap cheap cheap.