Which is completely pointless. In the same LCF configuation with the GM/ISUZU you can get the duramax or 8. 0 vortec.
In the bigger versions of these LCF trucks, you can get CAT and GM does offer an 8 or 9 liter inline 6 (yes inline 6). diesel named, funny enough, duramax with 800-900foot pound ratings.