Re: OMC LU ,identify year and Hp

[Don]

Yeah, there is also an issue about the driveshaft oring. Some models had the oring on the driveshaft, others had the oring in the crankshaft with no groove on the driveshaft. Does your original driveshaft have an oring groove? You will need a longer water tube, I’m pretty sure your water tube will just pull down out of the upper grommet. The shift rod in the long shaft gearcase should fit right into the brass connector. Your picture of the new gearcase shows a water tube, so hopefully that is the longer one that you can use in place of your short water tube.
Once you have checked/changed the gear lube and replaced the impeller (and found the right driveshaft), you will want to check the shift linkage and make sure it is adjusted properly. These gearcases are very sensitive to proper adjustment, and will start jumping out of gear if not properly set up/adjusted. Repairs can be very expensive.
Post more pictures if you still have questions…D