The Continental F226 is a 6 cylinder L head engine with 3-5/16" x 4-3/8" bore and stroke. Displacement is 226 cubic inches. HP/torque depended on the application, governed speed, etc. but I believe runs in the in the 45 to 55 HP range for industrial applications such as power units and tractors (Massey 44-6).. In 1960, Checker came out with an OHV version of the 226 Continental L head engine. Everything I have found so far indicates the OHV version was used from 1961 to 1964. After that, Chevrolet engines were used. I have posted 2 pics of the Continental 226 OHV engine. Notice the distributor is down on the left side of the engine and the spark.
DnT TV provides the facts about the Graham engine. Contrary to common belief, Graham had its own 217.8 engine. It was cast at the Continental foundry. Graham.. The FO-226 was Continental's smallest OHV 6 cylinder engine and was made as what they called A vehicle or transportation engine only as compared to the other models which were also made as industrial engines. It is a cast en block engine and takes the same pistons as the F226. So the engine will need to be bored.