I've got a D16Y8 with a 4-1 header that I'm having problems get a gasket for.

I've tried researching the diameters inside and out of the header but cant find anything and the header is on my car right now. Does anyone know the diameters?

 

go to you local auto parts & see what they have.
that's what i did..

 

I did that, Napa gave me a metal ring type deal (Didnt work) and Autozone was out of gaskets and only had a universal one which obviously isnt big enough.