here is a thought i had on turbo charging the 6.9 or 7.3.....use a borg warner gm4 turbo....they were originally made for the gm 6.5's, the are completely non electronic, wastegated turbos, i used one to turbo a 6.2 and i really had to adjust the turbo controller"i fab'd" or it would crank out 25lbs boost pretty quickly, anyone got any opinions (they can be bought cheaply too)

 

I see now reason why it wouldnt work, it should be ratioed correctly, and if you can get a good price on them go for it!

 

i second that
for a 6.9 should work well