I don't think they'd be real loud if you're running the exhaust through the cats first anyway. Older cars w/o cats and especially with headers will be louder.
Now what WAS fun, was back in the day when I put headers on a friend's Blazer (old-school full size with a 350). He wanted it loud, so for mufflers I put on 1980 Camaro Z-28 resonators* which LOOK like mufflers but have all the silencing ability of tomato cans. :wacko: After a week he took it back to the muffler shop and had turbo mufflers put on. :lol:
*Behind cats they sound pretty good. Trust me on this. That was the Z-28 system back then.