intake manifold casting ?

[jreb333]

i have a intake manifold with what looks like a big letter "S" cast on the top of it. what does this mean?

[68F250]

What's the casting #? They are not bad intakes depending on which "S" intake it is but they still weigh a ton.

There were several "S" intakes from '66 to '68. The "S" intake was for the car line while the "T" intake was for the trucks but I have seen several cars come with the "T" intake stock.