Yeah, The Flex-Pipe Doesn't Work...

Not cheap, but I'm sure Waldrons would make you just the y pipe in aluminized or stainless steel. Nothing sounds better than the original HP exhaust on these cars.

https://www.accurateltd.com/A-Body-HiPo-Exhaust-System_p_195.html
https://waldronexhaust.com/product/...uda-v8-273ci-4-bbl-carburetor-single-exhaust/