Best Coupler???

[Ted]

I am putting in 2 HP500 EFI's in my boat and figure I will replace the couplers while the engines are out, here is the weird part. The engines had 2 different couplers on them. On has a long nose and one basically has a flat nose. Looking at Mercruiserparts.com there appear to be 3 different Bravo couplers available for this engine. A long nose one. An aluminum standard one, and a steel standard one. And a Design 1, 2, and 3????? So which ones should I buy? Apparently they will all fit since mine had one long and one short, but what is the best one to use? Why?

[Griff]

I used the steel long snout when I replaced the one on my 525SC. It worked fine and I never had any issues. I would use it or the short steel one. I would not use the aluminum one.

[mbam]

Ted, there is a potential clearance issue using the long coupler with an early drive. The long coupler is designed to hold grease so the new input shafts have an additional O ring and machining. The old one's had 2. I posted some measurments someplace, might have been the other place. I think it was only an issue on a thin transom.