Lots of threads on Headers, but how about one more quick one!

IMO,
you would be hard pressed to prove One "style" of header having more or less power than another. The performance of the header is mostly governed by it's length, The install, and the ability of the tuner to get all she's got out of the combo, with maybe,the number of bends in the pipes playing some small role. But even if you could, as an average and expressed as a percentage over the powerband, it would be very very tiny.

As an aside, I ran a fenderwell set in a 65 V100 with a 340.And she was a streeter. And A straight-line streeter, cuz turning it sharp was OUT! And when you park it, make sure the wheels are mostly pointing straight ahead.
I would not ever do that again,lol
But they sure looked cool!