I need a new input yoke (part that goes into the engine coupler) and I'm not sure which one to get. BAM's site shows two numbers: 59830a7(early) and 864244a01(later). I don't know the serial number for my drive. Are the two yokes interchangeable. If not, how can I tell which I need. The boat is a 1991 but I can't say for sure that the drive is orig. Thanks!

Either one will work.

Are you changing the whole assy. or just the yoke. I think the cross bearings are different and won't inter mix.
Jim