I have not seen anything that says billet wills increase the EGT, lots of hype about just about aftermarket part on the truck so I would take it all with a grain of salt. If you can get a balanced center section with new wheels that sounds good. I would get the locking bolts for the center section. Good time to do a regulated fuel return while the turbo is out. Take a good look at the pedestal while turbo is out.
Early 1999 F350 AUTO 4x4 CC LB DRW 4.10 6.0 trans cooler, Front hitch, 2,000 hubs/ brakes, Bilstein shocks/steering stabilizer, Diesel site coolant filter 203 thermostat, EBV delete, new O-rings, new Oil cooler, RIFF RAFF FRX, Glow plug led, Pillar gauges, Lighted cupholder, Painless wiring fuze block, Harpoon/hutch mods, Removed axle blocks. Air bags, 5 wheel hitch, In bed 7 pin plug. Spare tire key delete. KLHANSEN on speed dial. 75,000 as of May 2019