Header gaskets for 302 heads

I've been looking for "reuseable" gaskets for my 87 318 with "302" heads.
Either Aluminum or Copper would be OK, I think.

I see there are at least three different port sizes.
I can find "340-360", and "Magnum 1992 and up".
Interestingly the "318-360" are somewhat difficult to find.
Which are closest to the 302 size?

How much will it hurt to run one of the others?

Not sure what brand of headers they are.
They are hanging on the studs right now and seem to fit pretty good.

Should I assume the headers are made for a 360 head exhaust port size?
In that case I doubt the gasket port size would matter.

Thanks