Old Iron,
I would bet, unless someone changed it at some point, your 46 Stylemaster had a 216. I don't believe they ever used the early 235's in anything but trucks.
I've owned 3 1946 sedans and all of them were 216's. I currently own a 1946 1/2 ton w/a 216 and a 1952 1/2 ton w/an early 235 (that came from a 1948 2.5 ton truck).
Visually, looking at an early 235, you'd probably never know the difference between it and the 216. The difference as I understand it was in the stroke.
The only visual difference I've ever heard of was some of the early 235's had 235 stamped on the oil pan. I say some, as I'm I don't believe they all had the imprint on the pan.
Both engines had the valve cover with the two nuts you described. They also had the side cover that extended up and around the spark plugs.
