Manifold gasket choice

My 340 with stock manifold drivers side has a 1/4" spacer that cured a clearance issue with my Eddy heads. I was hoping to buy these from summit but they are no longer available. I used them on my RB motor and they last forever. My stock gaskets last 2 years and getting tired of changing them all the time . Any suggestions.
Taylor Cable 66037 Taylor Cable Seal-4-Good Header Gaskets | Summit Racing