Mercury Outboard AB Lower Unit Pin Gear to Propeller Shaft 13-20937 Mark 20H Power Steering but can be easily obtained

but can be easily obtained on eBay

but I believe the 86-90 tubes are similar on the 5

MerCruiser Sterndrive Alpha One Lower Unit Complete Gear Set 43-17064A3 (17T/28T) (Gears only - Pinion

Might be high speed

Mercury Outboard AB Lower Unit Pin Gear to Propeller Shaft 13-20937 Mark 20H Power Steering but can be easily obtainedItem Description Mercury Part Number 13 20937 Set of 5 as pictured. Found on Mercury AB Racing Gearcase Lower unit If you are unsure on compatibility feel free to ask! Purchase with confidence! General Disclaimer (please read) These are New Old Stock Parts from a large mercury Mark & K models cabinet I have. Some of these parts might work on more models than listed in the title and or the description, Please do your own research There might be some