Ok here is the break down. 1987 350's rebuilt in the past few years practically no use since re-build. Port motor had a bad vibration, shop pulled it found the flywheel was 180 out from correct. Re-installed and runs much smoother. After inspecting the flywheel it is weighted. Engine builder said to not run that flywheel as it will tear up the crank as 350's are internally balanced. I agree with that entirely. My question is would you notice if the flywheel was weighted other than looking at it? Would the motor vibrate? Any other tell tale signs? Reason is starboard motor runs great. I wonder if I have to have it pulled also to check the flywheel.