I just installed my Flowmaster axelbacks on my GT. They sound great but I am having an issue with the driver side fitting in the cutout properly. Is there anything I can do with the hangers to make it centered in the cutout better? It really looks bad like that IMO.
You can adjust the fit with the angles at the after cat attachment point or you might have to loosen the mid pipe and rotate it. Go here http://www.corsaperf.com/installMustang.pdf and there are some instructions at the end that show how to make the adjustments and will work for your Flows as well.
you can also search the exhaust threads. i know that several install/adjustment tips have been given. they are pretty universal pointers for S197s. one brand usually has the same problems as the rest.