Question about converter.

yeah dude, it should. The high flow cat will open up the pipes more and give you a bit more sound and maybe even a small boost in power.

I did that with an old firebird I had, calmed down a bit of rasp and made the exhaust sound awesome.

not sure, the header will add rasp, but keeping the cat or adding a high flow cat can help the rasp.

if you swap the header that cat will be gone, but if you leave the other cat you should be fine.