Hmm..., if you're current tire diameter is 34" and you're moving up to a 36.8" diameter tire, that should only increase your total height by 1.4". Isn't that the way it's supposed to work? So, you still won't be able to fit because that's .15" too high. But, if the 36.8" is not the true height, and it's actually lower, then you'll be fine. Did you say that you don't have the air suspension now? Then, just throw a couple of salt bags in the back to weight it down until your tires wear down enough to fit into the garage without the extra weight.
