My son had a 350 built by a speed shop 4 yrs ago and the motor is still on the engine stand. He died and I have the motor now. I was told to spray penitrating oil, followed by shot of oil down the spark plug holes and turn the motor by the crank bolt. I did this and it turns but not easy. I used an 18" 1/2" drive bar to turn it. Any ideas? Maybe it is suppose to turn tight. Will it need to be disassembled?