I have a 81 1500 4x4 chevy,350 3-08 gears,4 speed with a carb getting 15 mpg,running 31 10.50 15 tires.Summit has a wiring kit for your tranny to lock in the torque converter.In town just leave in drive,on the highway leave in drive,unless your on flat land,then you can use the od.In drive on...