I think newer oils and frequent oil changes will keep it from clogging in the future...line size doesn't matter because there's a restrictor on the head that drops oil pressure down to a trickle in the upper end...it's basically gravity at that point pulling it back to the back of the motor (a bit of an exaggeration)...also, make sure there's a thermostat in it...it should be fine as is.
1953 Special Riviera 45R
1965 Skylark Hardtop 300-4V
1965 Mustang (in the family since 1968)
1965 Corvair Monza Convertible