M-37 Downpipe flange leak

[Chip Sandage]

I'm having continuing issues with the exhaust flange leaking between the down pipe and exhaust. I've replaced the gasket several times. Every time I do this the two flanges seem to be misaligned. I loosen the hanger brackets and re-align the flanges. Install new gaskets. I'm thinking it's the continuous heating and cooling that causes this. Perhaps different bolts? Stainless Steel?

I found this on E-Bay from John Bizal (Midwest Military)

https://www.ebay.com/itm/274658138085