I have L56 and the owner manual said it was rated at 190hp@3400 I believe the L65's have the 195hp rating.
All the 1500 trucks I believe are L56 and the "standard duty" 2500 also L-56. The "Standard 3/4ton" have the 6 bolt rear wheels, heavy duty 3/4 8 bolt wheels. Just a quick way to ID.
