Well... where do I start... The pump under the hood is for the 4000 watt tank heater, it has an electronic controller in the cab. I converted the truck to 12 volts and modified the front battery mount to hold both battery's. The passenger alternator was out so I replaced it with a Nippon Denso aircraft alternator. I added a third battery mount is for the aux system witch powers the stereo and the headlights. I upgraded the headlights to 6500k HId's(I know LED's would be better but when I did the upgrade LED's were very expensive). I rebuilt the Kingpins and upgraded to 265/75/16LT tires. When I added the civi trailer hitch I added around 50 pounds of extra steel for bracing, and a 7 pin light plug. When I purchased the truck the exhaust was trashed. I put on 45 sweeps with turn downs. I cut the mufflers out and installed Cheery Bomb glasspacks(which I love!) I pulled out the glow plug card and installed a manual switch. I installed 2 Led lights on the top back of the box for reverse lights and installed 4 oval Led's in place of the stock brake lights. 2 hard wired battery chargers that power on with the tank heater and block heater.(I have 2 different engine heaters depending on where i am, most places don't have 30 amp twist lock outlets). The generator, welder and air compressor work perfect. I use the compartments to hold tools and equipment. At first the truck was a toy(a really fun toy) and since then I'm self employed and I take my truck to every project I do.