KB Headers
They are a very nice design, equal primaries to a collector not a log type header so they have better flow characteristics. KB used to say the design of crossover into passenger side header was designed as to have a smoother transition and not interfere/disrupt exhaust flow out of passenger side header, so the flow from both banks was not as turbulent(run into each other) but more laminar(flowed together smoothly to turbo) which equated to responsive spool up.
That SS sure polishes up nice. Quite a few Years ago a friend of mine asked Mr. Dutweiller when he picked up his rebuild, what he thought were the best aftermarket headers out there(at the time not alot to choose from , and TA's weren't around) he liked KB's then ATR's and lastly Hookers . Are you pickin up a set or are they goin to be available for 650, those are sure nice. They'll look good on that engine of yours.