Diesel Bombers - New to Diesels! Not new to bombing!

Hey everybody! I just bought my first diesel. She's a 85 F-250 4x4, 6.9l, 4-spd, 4.56 ratios. Ext cab, long-bed with the EXPLORER package. Used to tend to horses, pull their trailer and everything else. I don't have multiple trucks. I have a background in off-roading. Jeeps, trucks, tanks, APC's and school buses. Looking to see what I need to do to make my truck the most it can be for the least amount of money. I know alot of this is making sure you use the best you can, when you can. First I gotta do is take off the 215/85r16 tires and get something on there that will let me do over 55mph! I figure now I got the power, and for the first time, putting bigger tires will actually help my mileage! LOL Luckily my neighbor knows diesels, my brother is a diesel mechanic and I have about 20 diesel mechanics at work. But, I like doing my own stuff. I am open to all suggestions though. I look forward to being BOMBED with all of you. Thanks for the tips already!:hellox: