Copper header gaskets??

[Olden Days]

I just put on some copper header gaskets trying to get a leak fixed (cause thats what they claim to do well) and it leaks worse than the regular header gaskets, but my question is... How do you match the proper gaskets? Do you get the round hole ones to match the header tubes or do you get the square hole ones to match the square ports in the heads??... what I did was get the square ones to match my BB heads but now I am wondering if I should have done it visa versa... anyone ??...