You are asking the wrong questions.

With thirty minutes on the motor, I would chuck the lot in a box and drive back to the builder. Take a tent and camp on his lawn until he puts a NEW MOTOR in your pickup. What he does with the old parts is not your affair.

DO NOT, DO NOT, get involved in discussions about valves, pistons, spark plugs, politics or religion.

If you are a little guy a pick handle would be handy too.