if you want a block heater that year cummins is very easy to install, I believe in 97 for the B series they switched to the ISB style block, both my 97 and 98 cummins are ISB style blocks anyways, they have 3 frost plugs on the side of the block instead of 4 and right behind the oil filter is a 3/4" NPT plug for a block heater so you dont have to mess around with getting a old frost plug out. take the pipe plug out and screw in a heater and your done. part number for a zero start brand 750Watt is 3500022. the 8.3L C series use the same style heater thats 1000 watts but I'm unsure if the element is longer to a point of not fitting, the 1000 watt part number is 3500032 if someone wants to try it. I have two 750 watt heaters in mine, A screw in one and a frost plug style ( part number 3500030) that way I have a choice of running one overnight at home or running both for a fast warm up at the camp.