I'm pretty sure the IC inlet and outlets are also 2.25... well, They're actually metric, but that's the closest. You would be wise to verify the measurements before ordering, but I do think they're 2.25 all the way around.... the piping on the other hand gets TINY in some places...
I prefer siliconeintakes.com for couplers and clamps. They've got good prices, the products are good and they always get me my stuff quickly.
Couplers:
http://www.siliconeintakes.com/index...4786e8f2214982
Clamps:
http://www.siliconeintakes.com/index...d24a1060d8e956
And no, I'm not an ad rep for them. LOL