I have a 1993 Chris Craft Concept 218 w/ a fuel injected 5.0L Ford motor. Im 99% sure the boat has an OMC Cobra outdrive (see attached photos) with a 21:18 ratio upper gear unit. I just bought the boat and it came with a good working lower unit but needing an upper one. I'm looking to order a used one online but want to make sure I order the right one. Now its my understanding that the 86-93 5.0L Ford outdrives are all the same and can bolt onto any year, is this correct? Its also my understanding that the 86-89 3.0L upper unit has the same ratio and can bolt onto a 5.0L Ford lower unit, is this true as well? And if so, are they built with the same gears or are the gears in the 3.0L weaker? And do I need an upper unit with the same model number or will i be ok with any model number as long as its the 21:18 gears? The model number is hard to see in the picture but its 985687
