The 68340 headers are a 1 5/8 tube (wrap around the chassis), long tube design.
The source is Super Exhaust Warehouse located in California.
I recently ordered their PN HED 68340 online at http://superexhaust.com for $ 311.26. I've seen these priced over a hundred dollars more. Also shipping was FREE via FED EX ground.
Even though my parts were back ordered, and I'm on the opposite coast, I got them in about 2 weeks as I was told.