David, good question but as I did on the engine change using Cessna's data that Cessna changed the 172 from the O-300-A to the O-300-C,D, & E Series engines with the 6 bolt prop. It was logical that it would be the same on the 170. ( The FAA could not argue the point). I installed the latches on mine but, haven't looked at paperwork or what I did was any different than what Cessna did to the doorpost when they changed over to the new style latch. I would think we did the same thing they did (to make it fit and work) and the doorpost modification was approved by their certification of the model year it was installed from the factory. I am reading this and hope it is a clear as mud-- I know what I am trying to say just not sure it came out the way everyone can understand. Ron
President 86-88
53 C170-B N74887, people choice 2003, Best original B 2007
46 7BCM champ N2843E Rebuilding stage
Cajun Connection way down south, most of you are yankees to me!