I knew that some of the early Cessna 172 had the Franklin 180 and possibly the 220 in the type certificate, but I didnt know that Cessna 170A/B had the 165 in the type cert. I remember seeing one for sale years ago, and figured that it was put in with a One Time STC, but maybe it was original? Just another little blip in the history of our engines. _____Grant.