You know there are several kinds of motor oils around. I just wonder what oil I should use. I got a 77 small block chevy with around 100 miles on it. It has conventional oil in it now for the break in, but I am thinking if I should switch to a full synthetic or a synthetic blend later on. And if so, do I have to flush the engine to make the switch. I have also heard of many of todays oils not being very good on hydr. flat tappet cams. Any suggestions?