This is almost too embarrassing, but I have to ask. I am working on a friends recently somewhat restored 1st Gen '55 3100 1/2 ton. It has the small six which has been rebuilt and is running an external oil filter. What would be the proper oil to run in this engine? It has about 100 miles on it since it was finsihed.

Last edited by snaponbob; 06/25/2008 10:48 PM.