best ratio for 98 f-150 to improve low end torque

Can anyone give advice on gear set change. I have an 4.6, 4wd, powerdyne supercharger, cat back exhaust. Combo runs well, but has always lacked bottom end. Currently have factory 3.73 ring and pinion. I am considering a 4.3 front and rear with an electric locker for deep snow. I don't know if this combo will be worth the $ and I don't know the effect on the highway rpm.

Your help would be appreciated.