[68Timber]

It's hard to say, it might run till the end of time with no issues. Here's how I'd approach it. If it adds heat to the xfer case right there the tailshaft seal will take the brunt of it and if that fails you've got the possibility of transmission fluid getting on the mufflers. Now you're up to potential fire hazard/burning your truck down etc. I would want them to move the mufflers back. Is this a shop you've used before?