I went to 32" tires on my 3.42 TB and have the same experience; just wanted to add that my truck won't stay locked up in 4th on freeway overpasses. It's a bit ridiculous, and quite a bit worse than I thought it would be. Trucks these days are designed very well, and when you change the operating parameters there's going to be a price. Go to bigger tires on an '81 Scout and you'll INcrease the milage, if you notice any change at all.
Right now the solution is to just drive easy. Down the road, 4.11 - 8.6 - G80... but that's time and money away. Daily driver, and I enjoy every minute of it.