I agree on getting an exhaust system, but Id go with one of the stainless systems like MBRP (?) or something. Theres one or two that are commonly advertised for the dodge diesels.
Youre going to need more air to get the heat down soon. You might be looking for a new turbo if youre at 32 and its getting hot. You could do turbo and exhaust at the same time for under $2k and have a full 4" system all the way back.
You can safely raise the timing to 16.5. I run 18 but thats a little more risk.
You could run water/meth but thats even tougher on a headgasket.

 

So a larger exhaust would make that much difference on EGT?I still have the stock one on my truck.Maybe I got some wrong info that larger exhaust would not effect EGT...

 

i would assume bigger exhaust = more flow, except for the fact that the valves control the flow out of the motor. in my experience with the factory 3" exhaust somehow the muff and cat fell out of there and i lost a lot of egt. i was around 750-800 cruising down the road and now its around 600. it used to go up around 1200* if i stayed on the juice but i just regulate the temps with my go pedal.

 

Found my timing had slipped to ~7degrees. Had it adjusted to 16. Egt's come up much slower now. Still gets over 1300 if I stay in it over 100 MPH but ALOT better. Power is less in the low-end and better in the top-end. Can't wait to try towing the race trailer....