Hello,
I've been following this thread because I too am rebuilding a 326 right now. I was hoping to clear something up regarding the head gasket discussion.
The nicely contoured 350 specific gasket is just that, a 350 gasket. The combustion chamber and "notches" in the bores are offset to the outboard side on the 326 and that 350 gasket would be a big no-no on a 326. It would be nice if someone made a more contoured gasket for the 326 as I hate giving up the compression using the #8518 but it will do the job as mentioned previously. Here's some pics of mine showing the off-center chambers and notches.
Just trying to help, Ron.