I would be more concerned with installing an "X" pipe then using crush bent tubing. Mandrel bent is okay but you really won't see much of an improvement on a mostly stock motor and street driving... especially a small cube one like your 283. Put an "X" pipe in ahead of your mufflers and run your dumps (loud and barky) or put on a couple of 2 1/4 inch tailpipes to mellow out the sound a bit. Going to a 3 1/2 or 4" tip will also help to smooth out the sound.
You choice of course, run it dumped for a while and then put on tail pipes when it becomes annoying. Don't be concerned about crush bent pipes... they will flow just fine for your set up... and they are a ton cheaper too.