Well, I managed to cut off the old mufflers and get a couple Thrush glass packs under there. The pipe from the muffler back was actually in pretty rough shape, so I just cut out a couple good parts and now the exhaust dumps out right in front of the rear axle. Is this going to be a problem? I did angle it down, so it's not blowing straight back to the axle or brake lines or anything.
By the way, it sounds pretty cool now. Can't wait for the packs to break in.

Thanks to everyone who replied!