My '07 is nearing 100,000 miles and I predict my auto trans will need to be repaired/replaced in the not too distant future. Should I save up and put in an upgraded trans, such as Goerend's, or trade it in for a new truck with a better trans? If I trade, I want to get into a CC, single cab, short wheelbase and put a welding bed on it. I would be getting an Aisin trans in that unit. I haven't ever gotten fuel mileage to brag about in my '07, so hopefully won't be disappointed with the 6. 7. Any thoughts?