ended up with diamond eye. 4" straight pipe is 4" straight pipe for the most part. $245 shipped so I'm not complaining. Got it installed today. Took me ~3 hours by myself on the floor but probably 2 hours of that was getting the old stuff off. I had issues with my sawzall which slowed me down quite a bit. I still have to get video but I'll need the wife to help with that so hopefully in the next day or two. Love the sound. Not near as loud as I expected and I'm not sure what drone people are talking about but it's not bad at all. Just sounds like a gas burner truck with dual exhaust to me. That is until you drop the hammer.......that thing roars at WOT. Love the increased turbo sound too. Money well spent IMO.