straight pipes?

You'll get tired of the noise soon. Here's a discussion on /6 exhaust: http://www.slantsix.org/forum/viewtopic.php?p=281813&highlight=turbo+muffler#281813
Here's more than you want to know: http://www.slantsix.org/forum/viewtopic.php?p=270708&highlight=turbo+muffler#270708 Both on slantsix.org .