don's 37
Senior Member
Just a quick question. I'm ready to start up my 1937 Ford fordor with a rebuilt engine and take it for a ride and it's break-in. Right now I've got Quaker State 10W-40 with the Lucas zinc additive in it. Should I go ahead and use what I have or switch over to a 20W-50 Castrol, etc. brand with the zinc already in it? I know a lot of you folks like the 20W-50. Thanks!