Quick update regarding the leakdown test: I'm definitely losing pressure, from 7 psi down to nothing in less than 5 minutes. I can hear air hissing out from underneath the flywheel, which means left crank seal is bad, correct?

Also, I'm measuring from the RIGHT side of the carb intake manifold (left hand side blocked off) and losing pressure. Does that mean that the center crank seal is bad as well?