First off, in a 7.3 there are 2 big humps for most people....1rst is the Rods. Yours are most likely PMR's are those limit a bit of power. 2nd is that 4r100 auto trans. It doesnt hold that much horse for long without vomiting and kickin the bucket. If your trying to make 400hp i would suggest Beefing up your trans, Torq Conv., then stop by Raul @ stealth-auto (link in my profile) and get a TW chip.. Gauges - get yourself some basic mechanical ones. I dont trust any of the elctric gauges on Edge programmers etc(just my personal opinion, and not saying anything against people who use em). So to give you a bullet list
GET THESE FOR SURE:
1)exhaust 2)gauges - get a pyro, trans temp, and boost 3)cold air intake 4) Custom tuned chip for your 7.3
BEEF YOUR TANS AND TQ conv(not sure if your auto or not)
then get your propane or water meth, run looney's or hot tunes, or new injectors (<-- lot of fun)
That should save you the pain of dropping ur trans onto the pavement
And if u dont have the $$$ to foot for all that performance u can always play with aesthetics like train horns, PA systems
just my .02 but i'd do it in stages and play it safe. Good luck bro and welcome to the org. Its more addicting then crack