MC exhaust manifold gasket questions...

[OorQue@aol.com]

I'm looking for an exhaust gasket with an opening ever-so-slightly larger 
than the OEM gasket opening because it slightly blocks one edge of two of the 
exhaust ports on my now-ported head (more on that later).  I cut one in half 
to see how thick the flame ring is and found that it's not thick enough for 
me to get away with "porting" it much, if at all.

To be honest, I'd really like to find a source for an off-the-shelf copper 
gasket -- unfortunately, I don't have enough time to order them or confidence 
in my ability to try making them myself -- but barring that, can anyone 
suggest an aftermarket brand whose gaskets run a little large?  I've tried 
the Sabo gaskets from Brazil as they're the only ones I could find locally 
but they were virtually identical to the factory ones.  Any other hints?

Thanks!

JG