For those seeking proper gear oil for the SM420, today I made the drive to several sources and came up with two places that carry/stock or can readily get the SAE90 Mineral oil required.
Price was about the same 18-20 dollars a gallon.
NAPA has the following:
[img]http://www.spicetraders.com/photos/sae90mineral2.jpg[/img]
I bought a gallon today.
While over at Tractor Supply Stores I found this:
[img]http://www.spicetraders.com/photos/sae90mineral.jpg[/img]



Baking in the nice desert sun, breathing life back into a 48 3800 5 window.