As an insurance make sure that Jasper "primes" the whole oiling system.I run an
oil cooler which I hook up to the engine and remove the distributor ,insert a primer tool and pump the
oil thoroughly through the whole engine.A lot of times damage like that is done in the first few minutes before the motor even fires for the first time. The
oil beter be everywhere before it fires. 20W50 oil is perfectly Ok .To explain simply ,it is as thick as a 20w oil,but with the additives it works like a 50w oil.Good Luck