My recently acquired project truck has not run in four years. I want to turn the 250 motor over by hand to see if it is locked up. I’m thinking my best bet is to thread a bolt into one of the tapped holes on the harmonic balancer and then put a socket on a breaker bar and turn it that way. The threads have been gunked up with paint and I want to chase them with a tap. Does anyone know the bolt size and thread pitch? ¼-20?, 5/16-18? Something else? Is this the best way to turn over the motor, or is there a better way? Thanks in advance for any advice!
http://67-72chevytrucks.com/vboard/a...1&d=1488545751