Terry  and fellow learkers
the reason I suggested before the oil change is to limit the amount of junk
suspended in the oil
as a rebuilder I have a hard time telling people to modify there oil that
can get tricky and if its the first time you are adding marvel then you dont
want the slug in the oil for the whole 2 or 3k miles
I have seen the benifits of marvel after 1 heat cycle in my own cars
Bob