The Old’s and Buick motors have some serious oiling problems. It’s pretty much common knowledge at sustained high RPM’s in any motor the oil will stay in the heads, lifter valley and various other block cavities. That’s why any serious endurance race motor the oiling system is converted to a dry sump like in Nextel Cup. However very rarely does this endurance situation happen in an airboat so the best simple solution is to install a large capacity oil pan which I do on every airboat motor I build. Sometimes on my own personal projects I try other way's. Just look at the physics of it. The oil is pumped up to the top of the motor under 40PSI to 80PSI of pressure but returns back to the oil pan with only the force of gravity. So it doesn’t take long for a motor at high RPM’s to run it’s self out of oil. It is easy to tell because most all motors always kick the same exact rod because the way the oiling is prioritized. The last bearing journal to get oil is the one that always goes first.