I own an 1999 International 4700 box truck with a sleeper known as an expediter truck. I want to know is it practical to convert it to a electric vehicle with a diesel generator backup. Average length of travel is 500 miles a day. total gvwr is 26,000 lbs. current motor is a dt 466e @ 210 hp and 550 torque with a 6+1 spicer transmission and a rear end of 444. Want a cleaner enviroment and use less fuel. If it hasent been done Id like to try it.