I purchased a CMI Header from a performance dealership that went out of business. It was off of a Merc 500 EFI. They also threw in brand new tailpipes and clamps and I need to know if they are compatible. If so, what clamp and gasket do I need? Rope style? Flat gasket? I've heard so many conflicting stories (bench mechanics) that I don't know what I need. I've included pictures of header, tailpipe, and clamp. If these are not compatible, what parts do I need?

Here are 3 more pictures...

flat gasket

I agree, the flat gasket is the one. Everything you have there looks right to me.

It is the flat gasket. Looks like a good little set up too! Fred should have them for CMI. Where are you located, maybe there is a local dealer?

Thanks for your fast replies, guys. Sounds like I need the flat gasket.

You will need the flat gasket. I use 2 per side. If you buy them direct from CMI they want way too much money for them. You will also need the molded U hose that connects the header to the tail pipe. The pictures do not show the bolt & nut that go with the clamp. You will need that also.