Engine Torque and Horsepower

... if they are operating at different speeds.

Same operating conditions? Torque, rotation speed, and horsepower are linked by a mathematical formula.

Why do you ask?

Very little is ever "identical" so a variance of 3-5% might be acceptable.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

To clarify that point ...

Two "supposedly identical" engines might produce different torque (and therefore horsepower) at the same RPM due to inherent production tolerances, or historical wear (piston ring sealing, bearing wear), or different operating conditions (coolant temperature, oil temperature, intake air temperature, fuel quality, and a whole bunch of other factors) BUT if they are the same RPM then the torque and horsepower are mathematically linked, because one is a mathematical construct of the other.

I'll now ask the OP do you know the relationship between Horse Power and torque? That will help with your question.