stay TH350 or convert to 700r4

[ducksfootball82]

I am debating between switching from a TH350 to a 700r4. Based on what I have found so far it's as clear as mud if it's a good idea. I hear people love their 700r4's and other say to stay away from them.

Vehicle is a 72 3/4 ton, 4.10's, being a daily driver mostly in town with the occasional towing of a travel trailer and occasional road trip. I recently bought it and drove it up from Oregon to Idaho getting only 7.2mpg staying out of the secondaries as much as I could, cruising about 55. In search of better gas mileage. Any help is appreciated.