Originally Posted By: Merkava_4
20W-50 would lubricate those flat bottom lifters and protect the cam lobes. It would also keep those same hydraulic lifters pumped up. Y'all try running 5W-30 in that vintage iron and you're gonna get clickity clack from the lifters bleeding out.
I've run nothing but ILSAC type 30 grades in small block and big block engines of that vintage. I'd run some Defy 5w-30, or, at the outside, a 10w-30 VR1. There would also be nothing wrong with a reasonable HDEO in this application.
Did you know that Mobil yanked anything heavier than a 10w-30 (aside from Euro and motorcycle oils) in Canada many years ago? They don't even offer a 10w-40 up here, let alone a 20w-50.
20W-50 would lubricate those flat bottom lifters and protect the cam lobes. It would also keep those same hydraulic lifters pumped up. Y'all try running 5W-30 in that vintage iron and you're gonna get clickity clack from the lifters bleeding out.
I've run nothing but ILSAC type 30 grades in small block and big block engines of that vintage. I'd run some Defy 5w-30, or, at the outside, a 10w-30 VR1. There would also be nothing wrong with a reasonable HDEO in this application.
Did you know that Mobil yanked anything heavier than a 10w-30 (aside from Euro and motorcycle oils) in Canada many years ago? They don't even offer a 10w-40 up here, let alone a 20w-50.