I'm hoping one of the stovebolt historians can help me out.

I have a 1951 3/4 ton. My GM restoration pack tells me that it originally came with a 216 engine and it does not even mention the 235 as an option. The truck now has a 235, but it's an old, splash-oil 235, so the engine swap must have been done fairly early in the truck's life (I don't think anyone would have upgraded by putting in an old splash-oil engine once the full-pressure models came out).

So, my questions are:

Was the 235 offered as an option in 1951?

and

What year was the fully-oiled 235 first offered?