Nicolasticity

I have an OL serial number Bravo 1 drive about 1998 on an older serial OC bell housing. Changing gimbal and note that the exhaust is not the same as the replacement part I have which is a plain tube bellows pt 78458A which is about 5 inches long. Currently fitted is a std bellows whicj is longer as in attached picture.

I have a 425hp 454 from 1992. Gil exhaust.

Question is should I have a bellows or a tube. Can I fit either? Why is tube shorter than the bellows? Does the tube seal the exhaust or doesnt it matter? Does using an old gimbal and a later affect the bellows length or is it pretty standard?

PAST DUE

you can use either one or you can leave it off if you want a little more sound up on plane

Nicolasticity

I have a Gil thru transom exhaust and wondered why i'd get more sound on the plane?

Also with the non bellows sleeve it doesnt seem to have a clamp for the large end - I guess this is because it doesnt need to locate

Mr Gadgets

If I remember correctly.. the non bellows one clamps to the transom assy and then the drive when tilted down, lines up with it. If you dont have through prop exhaust, aka silent choice, then there should be a plate on the inside of the transom.. If you have that. leave the bellows off. It causes some issues with suction with the hub on the prop. Without the bellows air can freely flow through the prop hub..
I have run it that way for many years..

Hope that helps.
Dick