Hey everyone who thinks that it doesn't really matter whether you put synthetic or conventional oil in these old magnums ? I do have a aftermarket cam shaft and other goodies in my rebuilt engine that I will list and post. Do these older style engines even benefit from synthetic?

 

It won't hurt anything.

 

It's been my experience that 'synthetic oils' are better for the longer run of the engine because of their better flow and breakdown patterns. That said, the only time I'm aware the oil you use being critical, is during cam break in, but that usually only effects flat tappet cams.

 

Intresting. Im pretty religious on my oil changes so I never go past 5000km intervals. The only concern I'd have without using synthetic is cold starting in these Canadian winters. But I guess I could always switch to 5w30. I just did my timing cover gasket and I Believe a have a seeping oil leak from where it meets the oil pan so I was thinking maybe switching to conventional might slow it down?? Haha.
also I'm not sure if it's true but it can be harmful switching back and forth from synthetic ?

 

15w40 or 10w30 diesel motor oil is the best oil to use. You can use 5w40 synthetic like Rotella T6 if you want to but conventional is fine.

 

Not gonna make my aftermarket parts perform any different ?

 

After I switched to synthetic, I noticed a reduction in consumption between oil changes, and a reduction in what was in the catch-can.