If this motor still has the beer barrel manifold (kegger if you please) are you aware of all the trouble the factory base plates caused on these? Huge intake leak developes which draws oil from lifter valley, fouls plugs, smokes out exhaust, leans out cylinders close to leak and on and on. They were just stamped steel plate and the gasket blew out on most over time. Many fixes but aftermarket base plates and gaskets available from Hughes and others. Holding throttle plate open look for oil pooling in base of manifold with a focused light beam. Many posts on dozens of forums about this in years past. Hope this helps
