[Dave50]

I have a 1966 Mustang 200 cid 3 speed I just getting in to the old cars.I would like to know what would be the best oil to use. would I use a 10 W 30 or just a stright 30

[BrandKoe]

Not sure about the weight but I seen in an ad that today's oils are made for engines that use roller tappets, not flat tappets like the older stuff. To remedy this they created a new line of oil with more zinc (I believe) and probably some other stuff too. Could be just a sales pitch but something to consider.