I read in the Seloc manual that there were two kinds of bellows. One like this:
http://i6.ebayimg.com/04/i/000/96/ef/a3cf_1.JPG
And one like this that they said helped reduce low-rpm flow (by not forcing it to go all the way to the hub) It only attaches to the transom side and just loosely slips over the outdrive side when you trim down.
http://i6.ebayimg.com/07/i/000/96/f5/df8d_1.JPG
Which one is better, and are they interchangeable? I would think the latter one is the better since it seems to flow more... any thoughts?