A buddy had a small block on the dyno with a cheap set of headers. The headers were drilled too low so they had a gap at the bottom of all the ports. We are talking about an 1/8" gap where you can see inside the exhaust port. Junk headers


He went through a Few sets and then I gave him my set of remflex . They sealed it. And never showed any signs of fatigue.

Post a pic but if your issu is at the sealing surface it will seal.