I have been looking at the common failure of the turbo exhaust manifold gasket (from engine to manifold). Seems like they warp and pull inward as the center is not supported.
If you look at the image you can see how the center is pushed up and the outer edges are pulled inward. This causes the entire thing to warp and is shifting under the manifold.

Looking at the gasket for the FD it is a two piece design which would eliminate the issue described.
Is it okay to use the FD gaskets on the FC? more so is it okay to modify the FC gasket to be two piece?

 

If you cut it right down the middle it will "stress relieve" it. I do this on 81-85 12A gaskets to fit NA 13Bs. I haven't had any problems. Go for it.

 

FD gaskets will work fine. i guess you could split the FC gasket too.

you have a "problem" and not really a problem. you're not really supposed to reuse that gasket anyways

 

Yeah, I've never seen one of those gaskets fail either.

The two piece FD gaskets are very handy for 13Bs which no longer have a commonly available gasket. Or 20Bs. Or 4 rotors...

 

I wont be reusing that gasket posted earlier. I want to use a new gasket, but cut it into two pieces to stress relieve it so that it doesn't buckle again.

Thanks for the input

 

Oddly, the FC gasket is ~$20 less than the FD, so cut the FC gasket and you're up beer money.

 

I've reused them and had no problems. I'd say it depends more on how bad it's condition is

 

Heres what I did

 

That looks like it used to be a 12A gasket. I don't know if the fold-over was necessary but you did it so good job.