Help from GMC/Chevy 1500 6.2L owners with NHT package.

I cannot find the article right now, but it was a GM forum with supposedly GM engineers answering questions.. The reason given was that the 6.2 all aluminum motor was nor designed for lugging a load around but rather for people who liked the git up and go. He stated that it is not available in 2500 or 3500 trucks for this reason. Thats why they still offer the iron block 6.0 as the work horse engine for HD trucks which are designed to haul a load, whatever it may be..