anyone know where i can get a replacement. I bought and exact replacement from napa a few years back but they can't seem to carry it anymore. It's for a 71 with disk brakes. i like the stock replacement cause both tanks are the same size and the bore is 1-1/8". the replacement they want to offer me now has a larger tank and a smaller tank. any help appriciated. cast number is 5468115 thanks, ARQ.