Kudos for thinking it thru. Very closely matched exhaust runs and anything that makes servicing easier is a plus. Your routing makes it so you wont ever need to take off your exhaust headers when you do belts and valves.
Did you get a double flanged connection where the muffler connects to the header?
Only 2 comments to nitpick.
1) I don't see 18mm lambda / o2 sensor ports on the headers. I would suggest you put one independant bung on each header run for future tuning.
2) I always like a slip fit w/ spring on each header to allow for the system to expand a bit due to heat.
This is JUST ME but I always have a worry in the back of my mind that hard locking in long runs of header without expansion adds stress at the header connection points. I see you have one on the vertical but I dont see one on the horizontal.
Excellent Job
