The early gs´s had roller bearing cranks and carried only 2 or three pounds of oil pressure so never use synthetic oil or an oil cooler on these. However the 750 e with the tscc 16 valve engine came with plain bearing cranks just like your car and also have screw type valve adjusters making valve adjustments a snap. I have put tens of thousands of miles on the older gs and highly recommend that you use castrol 4t oil. As you probably know castrol gtx used to be the oil of choice but epa regs regarding zink and catalitic coverters force castrol to reformulate gtx and it is no longer suitable for bikes so use the 4t. I recently purchased my 5th gs (my first was a new gs 550 bought in 1980)a 750e and I have decided it is the finest bike I have ever owned. The power delivery handling at speed and in the parking lot is better than any of my bmw´s or even a gs1100gk that I put 40,000 hard miles on. I like it so well I am looking at getting an 82 T model for sale on the internet. If you are new to biking get an experienced rider to make sure you understand counter-steering so you can stay alive out there.