so you got a sweet deal on a yamaha motor for your boat except it's the wrong length gear case? here they are, one is for a yamaha 150 outboard and the other i believe is for 200hp.
convert your short shaft lower unit into the appropriate size with these 5 inch (100% original OEM) yamaha gear case extension spacers. you can save a shit ton of money buying these here and then sourcing just the input shaft extension, shift shaft extension, and brass water pickup tubes elsewhere.
or perhaps you've already bought a gearcase that's the correct size you need, but it's to long to mount up to your powerhead. Heres your solution!

Who doesn't love an extra 5 inches?

OEM 04-2024 F150 150hp Outboard Extension Case 5" 63P-45211-00-8D 2016