Friend of mine has a seafood business, his father in law recently gave him his old hot shot truck, which my friend as of last week had a custom built aluminum cooler built for it and he'll use it to haul seafood all over the Gulf Coast. Being laid off last week, he asked if I wanted to work for him for now to which I happily obliged. He asked for me to do all the necessary maintenance on it before we start racking up miles, I'll be putting about 900 miles a week on it. Its a 2007.5 Ram 3500 cab and chassis, single cab, with the 6.7 Cummins, sitting at 525k miles. It has the 6 speed (I assume G56 Getrag), and its deleted. I'm pretty sure its 4wd but I'll check for sure tomorrow. My plans are to Replace trashed K&N filter (full intake is on it, not a fan of K&N but ill stay on top of keeping the filter clean) Change fuel filter every 10-15k Change oil and filter with either Delvac or Supertech 15W40 every 6-7k Change coolant (Should I use Zerex G-05/distilled water? any special process to bleed air on the 6.7? EGR is intact but turned off, DPF is gone) Change all belts if need be Change gear oil in rear(Valvoline 75W90) (not sure what to use in front diff and t-case) Inspect/grease ball joints Change fluid in G56 The G56 fluid is what Im hesistant about, everywhere Im reading that I should use either Schaeffers SAE 50 or Delvac 50 instead of ATF 4, and to overfill it by a quart......the only way to overfill it would be to pull off the shifter and fill from the top? Multiple sources have said to use SAE 50 and to overfill. Is the G56 the only manual tranny offered this year?