Motorcycle Repair: 1977 gl 1000, 20w50, 10w40

Question
I am restoring this bike.Bottom line what is the best oil for this machine? Does it have a common sump? What about best type of oil filter and coolant? Your vintage knowledge is appreciated !

Answer
Carl, I'd use a Castrol 10W40 or 20W50 if I was running in very hot climate.  Honda also makes a very good oil but it's expensive.  I always use Honda filters because they have the best performance an protection for the money.  If you buy a cheap filter and the paper collapses or ruptures because the pressure across the element was too high, you won't know about it until you are rebuilding the engine.  Use a coolant make for Aluminum engines.  They usually say they have high silicate content.

Regards
Rich