I agree with AFU45 - take the air out, and you take the risk out. I'm paranoid like you about the split rims. I took the stems out so I could walk away while it deflated. I was sure nothing would happen taking the air out, but why not be careful?
Of course, the downside to this is that you have to inflate the tire later, which definately IS risky, if not done properly. I'm guessing you're putting new shoes on your truck anyway, so you'll have to inflate them SOMETIME . . .
Unless you've got those cool, HUMMER run-flat tires . . .
-Michael
