160 HP 204 lb-ft torque
4 bolt mains is the only difference I am aware of.
I have this exact truck and based on my research, the engine option code for this particular model was LT9. Look at the sticker on the left hand side of the engine compartment. The factory ratings for this engine were done with all accessories on (full load) to give it a lower rating for insurance reasons. The engine specs are as follows.....8.3:1 compression, 160 hp@3800 RPM, 260 ft-lb @2800 RPM. Hope this helps.