1997 K3500 4X4 Dually Performance Questions!

Hi all,
Getting a new to me 1997 Chevy K3500 4X4 dually tomorrow.
It has the 454 Vortec and automatic transmission.

I am interested in reprograming the computer for better performance/mileage.
I did this on my '97 Tahoe 350 Vortec years ago and it has run great ever since.

Is this something that would be recommended for this truck? my local guy has retired and I can't ask his advice!

I can probably find someone local however I have seen some on line site also.
Any recommendations on who might be good?

Thanks for any advice!