130FE, Welcome to "The Bolt".
Your truck more than likely came with a 216, and someone at some point has changed it to a 235. There are some of the older 235's around that have the two studs through the valve cover, and the higher side cover surrounding the plugs, but I've not seen too many of them. (I do have one in one of my 52's.)
As Shipwright stated, the date codes are probably your best bet on verifying what you've got. You can always check the block casting number, if you care to do so, over at inliners.com.
As for the transmission, that would more than likely be stock/original. The 4-speed would have been an option for your model/year. And I believe the 3-speed would have been standard.
I would assume, unless you see the remnants of a column shifter having been there, it was original equipment. It's not real likely that someone went to the trouble of swapping out the steering column, when/if they put a 4-speed in.
Anxious to see the pictures.
