I would suggest to
Take it slow. First and foremost, get some gauges. You need to see what that engine/transmission is doing.
You can wrap up a TON of $$$ real fast. Then the real problem starts, what I call the cascade effect.
You get a big set of injectors, and/or a big hp box. Great power, really hauls ass, right? But, the EGTS are crazy high, so its time for a bigger turbo, aftermarket air cleaner and some bigger exhaust, or your gonna melt it down.
Cool. Good power, but now we need bigger fuel lines and different lift pump to feed the big injectors.
Ok, we got the big fuel supplying the big injectors driving the big turbo.
Done right? Nope, now your transmission/clutch is slipping or completely ripped out at this point.
See where I am going with his? Take your time, and learn as much about your new rig as possible. Do one step at a time. Do you homework about the mods you are wanting to put on. Talk to other people that are running the stuff your looking at.
The TDR is the biggest asset we have, and its loaded with a bunch of great guys that know a lot about these trucks.
Unless of course, your loaded and money is no object, in which case totally disregard this whole post.