3:55 gears on the street

1993 230horse V/8 auto Dakota 3.55 rear, the overdrive failed, locks up the rear tires.
Performed overdrive delete and run straight 3.55.
The truck don't care, I don't care. 2 mpg drop at 70. No drop in town. 300k and climbing.
Also have one with 3.91. Probably wouldn't work for that one.