That appears to be a later 235 engine, not a 216. The 216 has a side cover that extends all the way up to the valve cover, with holes for the spark plugs. Also, the 216 valve cover is secured on with two studs extended up from the rocker stands thru the center with acorn nuts, and the oil fill cap is toward the front. Look for the build date casting numbers down by the starter and the casting code toward the lover right front of the block. Those will tell you what year the engine is.
SAE horsepower is based on the formula Cylinder Diameter squared times Number of Cylinders divided by 2.5. Also called Tax HP in some places. The 90 HP rating is a Brake HP rating, and what's used currently. It reflects the actual output of the engine.
BTW, I had some confustion on your other thread it with your location. I assumed it was Waterloo, Iowa, as I'm most familiar with that city. You might add the state to your profile.
Last edited by klhansen; 09/28/2023 7:26 PM. Reason: added SAE HP formula
