Fuel economy and power output are too low for the cost involved with the swap.may I ask why you think it is a poor choice?
X2putting a carb'd 350 in your Jeep is a giant leap backwards.
I'd rather have a fuelie 2.5L 4-cyl over a carb 350...all day long and twice on sundays.
if you want help and guidance then here you go: rebuild the 2.5L and call it a day. put your money into the 2.5L, the axles and the gearing.