"That was a "3" engine code ..."

What is a "3" engine code?

"120hp x 1.25 x 14.5 = 2719 lbs + 50lbs for torque = 2250 lbs in ITA"

Is it just me or should that be ... 120hp x 1.25 x 14.5 = 2175 lbs + 50lbs for torque = 2225 lbs?