So I finally found a good deal on a generation 3 CTD Ram 6 speed manual. This is a 2004.5 325hp 4x4, quad cab, long bed SLT. It has 272,000 miles but seems pretty well maintained. A few questions.
1) The tires are less than 50% so was thinking of new ones already. They are stock 265/70/17 31.6" tall. There is a set of new 2016 take off wheels and tires from a 2016 in 275/70/18 that would be a 33.2" tall (for $600!). I think I have 3.73 gears but I can't find any tags and the sticker in the glove box is missing. I think that would drop the rpms by about 100 in 6th but would lift the truck .8 inches. Good, bad, wash? I can hardly buy new LT tires for $600 let alone on wheels ready to run.
2) Mainly this is to tow my camper. The camper also sits very high as it's built deck over tires to allow the whole wall to slide out. The camper is skinned under but does have some plumbing and the jacks and axles hanging down. Would letting the air pass under the truck be better (it's pretty high especially if I add the new tires), or would adding a lower air dam to the front help more?
3) similar lines with #2, the camper is tall and doesn't have much of an aerodynamic nose. I want to haul motorcycles in the bed and have thought about adding a ladder rack over them with an inverted jon boat for use as a boat, but also as an air deflector for the front of the camper. I could get a nice rack and a new boat for around $1000-1500 (much less for an used one). When not camping I could remove it all. I will try and hook up the camper once some snow melts to better visualize what I'm thinking. I could also add coroplast sides to the ladder rack to clean up that air as well and get the nose of the boat to "seal" to the roof of the truck with some cut foam.
4) any advice on when to shift and how low I can safely keep the RPM? It seems to want to keep itself above 750 rpm but would a lower gear be better then to keep to rpms even higher? That would mainly be while unloaded around town, on the highway it will be well over 1000 if not 2000 rpms.
I have read a lot of other advice here from Slowmover, Gumby79, Skyking, oil pan, and others so I am listening to all that advice. I'm going to take the truck in to Gomer's US diesel parts here, they are a great diesel shop, and have them give it an overall inspection and maybe add better fuel filtration if it doesn't have it already, fluids and filter, along with some gauges to start (EGT and low pressure fuel). I'm also considering a remote Fass lift pump with filtration. It does have some blowby but not enough to move the oil fill cap removed and inverted on the valve cover. The clutch feels like it has a lot of pedal effort, I can't imagine that is stock but I need to find somebody with a stock clutch to compare. It has some oil leakage on the front of the pan but not much. I will check in the morning to see if any has even dripped. It's supposed to be 8 degrees tonight and it's outside and plugged in so that will be a good test of a cold start (I need to do a lot of cleaning in the garage to fit this beast in there LOL). Anything to look for or listen for there? Shifting is going to take getting used to, 5th and 6th are kind of hard to find but man takeoffs are easy. Just put it in 2nd a let out the clutch, you don't even need to give it pedal but a little seems to keep it smooth. The overhead MPG says 20.4 and hasn't been reset for 9000 miles so that's promising. It has 7200 hours on it so that averages about 24 mph, not ideal. The only modification looks to be an exhaust brake, air bags, and a turnover ball in the bed (another not ideal sign), the air cleaner, exhaust, intake, suspension seem stock. I'm pretty happy, not perfect but so much less expensive than anything else I have seen, my total cost was $13,000 (with fees and shipping) and that gave my buddy over $500 profit as well.
I'm sure I will come up with 50 other questions as I go.