Trying to find any information on my car and 340 engine

Take it to the track and make a run. Stock they went mid 14s.
Make a note of the trapspeed. stock the went just under 100, maybe 98.
Weigh the car.
From weight and trapspeed the power can be calculated fairly accurately.
From the external cues, and Power, we can more or less tell what's been done inside the engine.
Accurate cylinder pressure can/will help