Hecty2000XJ

Hi everyone, I just purchased a full exhaust system for my 2000 XJ Sport with the 4.0. Everything is very much stock except I got a header instead of the OEM exhaust manifold. My question is does any one knows what gaskets if any does it take on the connection between the manifold and the catalytic convertor ? I have the dual catalytic convertor unit the one that looks like a Y ! All the other gaskets are included with the parts I order except the ones I mention. Anyone knows the part number ? Everywhere I look I can find full diagrams about the full exhaust and all the parts but not one mention those gaskets. Please help, Thank you.