A stock of the show room floor LT500R will make around 50 hp to the rear wheels on my dyno. 

The formula for horsepower is:

                                                HP = (Torque x RPM) / 5252


Torque and RPM were on most of the graphs.  On one of the graphs peak Torque of 57 ft.-lbs occurred ad 6500 RPM.

                                   Example:
                                                    (57 x 6500) / 5252 = 70.5 hp

This engine was not stock..... It had a big carb, head work, porting, and intake system and a HPR 19 exhaust system.

The sag or small dip in the power curve between 6500 and 7500 RPM after the power valve was properly adjusted, was due to the intake system's tuned length and porting not being right