Seems like a waste starting with a 4x4 and ripping the guts out to make it more fuel efficient. Would it not be more practical to sell/trade the 4x4 for a 2wd model? Around here a 4x4 would go for double an equivalent 2wd in the used market.
Swapping/trading for a 2wd you would likely make a bit of money on the trade and already have a truck that is lighter, lower, has less moving parts, smoother front suspension, and likely a taller axle ratio.
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