I was just doing some research on my 99 and I found this link:
http://flashoffroad.com/Diesel/GM99Diesel/6_5LV8TurboDieselSpecifications.htm
19.5:1 comp. ratio. Does this sound right to some of you? This means if I put an IC on, I can run near 15psi boost with out internal mods and don't have to be as concerned about piston crown temps etc. right? Provided all the other stuff is in place. Any thoughts?

It's been discussed here before many times, the updated 6.5's never made it into production trucks. There was just to many 6.5's in surplus to be used up.