260hp / 260lbs @ 14psi

But the graph shows the peak 260hp and the 5252 crossover…
If the RPM on the graph is wrong then the lb-ft @ XXXX RPM is wrong making HP (rpm * torque / 5252) wrong…

If the RPM on the graph doesn’t match what your actual engine speed was then HP cannot be accurate…

Not saying you made less hp or anything, infact if the rpm shown is LOWER than it was then you probably made MORE horsepower than 260…