Well my new '42 flathead is here and I want to perform all the usual oil changes and etc. Can I use synthetic or should I stick with dino? Will 20w50 be ok? My manual (a dept of defense reprint) says I should use at least 72 octane fuel (wow). Will the higher octanes of modern fuels be a problem? Should I add some sort of lead substitute to the fuel?
thanks for any and all replies.

 

I would get in touch with a good Oil Rep ... think could be critical what you pick and choose although 20W50 Dino seems within Reason .. I would try unleaded 87 Regular for gas .. Amoco proved in the 50's that Vehicles didn't need lead in fuel to run properly..

 

It wouldn't hurt to use the lead substitute. I use it in all of mine that still have the original valve seats. Depending on the temperature I would use straight 50 or 60 weight oil but thats just my opinion. The higher octane shouldn't be a problem. Post some pictures of your new ride.