I agree with Joe, Remflex are working great for me. I torqued them in three steps which may have been overkill and used locking header bolts. I have an old set of hookers that tended to blow out other gaskets.
I quit using header gaskets. I bought a set of Sanderson headers for the roadster. The instructions said not to use a gasket. Instead put a 1/8" bead of high temp red silicone around the ports on the head and let it sit overnight and cure. Then install the headers. It worked great on the roadster.
I had built a set of headers for the model t coupe and always had trouble getting them to not leak with gaskets. So I tried the Sanderson method. After putting the 1/8" bead on the heads and letting it cure, I put a very thin coating of silicone on the header flanges and installed the headers, I finally had sealed headers.
It's a lot cheaper than gaskets. You might give it a try.