I picked up a stat at Autozone using the Duralast p/n you listed for the higher flow. Also got a new gasket for it and and found the Duralast p/n is the same as the Fel-Pro p/n(#25565). When I slipped the gasket on it's a perfect fit, no slop, etc.
I didn't install it as yet, lack of ambition mostly since it's a bit of a PITA. Just passing on info....nothing more.
