I have a Slick harness (M1730) that I pulled off n O470L before it went in for overhaul. According to Slick's application chart this will fit pretty much any of the O, IO 470s and 520s using 3/4" plugs. This harness was purchased 2 years ago as part of a Slick mag kit. Mags have been sold and my O-470-50 got brand new mags and a harness with the overhaul so I don't need this one. It is in excellent condition and has right at 100 hours on it. $250 shipped in the lower 48.