I bought a pair of Corsa exhaust diverters from a member, In the process of trying to hook them up, I'm coming out of 4" stainless marine headers, the diverters are 4" round x 4" Round by 3 1/2 oval ( down pipe) . My y pipe is oval and I thinks it's 4 inch, but it seems more like 3 3/4. Seem like slack with a 4" hose on it. Do they make a 3.5 to 4" adapter, I really lost. Anybody have any ideas? Also can you slide a piece of 3.5 " over the down pipe then a piece of 4 " over the 3.5, will that leak?
Thanks for any help.

There is special oval hose for that connection. You can get them from several marine vendors.

Look at this site.. Looks like they have a couple reducers. I can tell you the rubber used on these is very pliable and will contour to Y Pipes

http://www.ebasicpower.com/c/VOL8D-IB/Bellows

Chris

This is what you want.


http://www.ebay.com/itm/2-NEW-MERCRU...70dcf5&vxp=mtr