I ordered a mandrel bent three inch exhaust kit from Eastwood when they were on sale a while back.
This may be the easiest way to get what you want.
It just takes some time and effort to cut and fit to your specific needs.
Then after it has been fitted, you can use band clamps and leave them.
Or then take it to a shop for welding if you cannot do that your self.
That is what my kid did for his '49 Chevy shown here with his buddies making it happen.
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This was just a temporary set until he figured out how he wanted to do his tailpipes.
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Now he has tailpipes routed all the way out the back of the truck.
Man did that temporary setup drum under the truck super bad.