Where to get pre bent exhaust pipes and any suggestions on how to swage them to fit over mufflers?

I like to do everything that I can here instead of relying on outside vendors or shops.
I saw these:

https://www.flowmastermufflers.com/...r_components/direct_fit_pipe_kits/parts/15826
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Does anyone here have any experience with these? I'm looking to swap the exhaust in my 67 Dart when I do the engine swap. It will have headers, an H pipe, Flowmaster mufflers and 2 1/2" pipes so these seem to be a logical choice.
Free shipping too.
The goal is to piece together a good exhaust system here at home without going to a muffler shop. I also need to know if there is a way to swage pipes to slip one into the other for a more positive connection.
Thanks!

Yes.

You will need an exhaust pipe expander.

This ones available at Summit but I bet Hr. Freight has one as well.

Titan Tools 51364 Titan 3-Piece Tailpipe Expander Sets | Summit Racing