H3 bulb style, 55 watt, 4500K bulb color. Should slip right in the light housing you've got on the rear renders or the upper ones on front of the cab. Will have to find someplace to mount the 3X4" ballast though. Maybe under the cab roof??
Lots of space under the roof but a lot of dust and hard to reach... How about the lights in front, the ones that are mounted in the hood? (Front and side worklights)