You people with the traditional Y-blocks may not realize how lucky you are.  The traditional Y's, such as a 312, are supported and you can even find performance parts.  Aluminum intakes, heads, cam's.  A whole variety of parts.  Try doing the same for a 368.  I walk into a parts store, such as Autozone or O'Reilly's and when I tell them I have a 57 Lincoln they then as if its a Premier, a Capri, or a MarkII.  The only difference between a Premier and a Capri is the power windows and seats.  Its like a F150 XLT and an XL.  And Mark II? Those are even Lincoln's.  They're Continental's.  Just don't ask a MarkII owner that question or they'll rip your head off.  The next question is what engine.  Really.  It doesn't matter which car you have but they're all the same.  368 Y-block.  I know.  I'm ranting.  But if you work for one of these guys you should be a car guy.  And NAPA?  They're just as bad.  

So when I need hard parts my options are places such as Kanter and Egge or the resto houses.  When I needed a cam for both my coupe and my convertible they were a couple a hundred each from MarkII.  When I needed a flex plate it was about $300 for a used one plus a core charge.  But in the end it's worth it.  Nothing better than the look and sound of a LYB.