[NoDOHC]

The front and rear headers are the same length, I wrapped them with super high-temp header wrap and I can assure you that they are the same.

I have some more info that I haven't fully digested yet, so before I post anything, I am curious if anyone has tested the exhaust backpressure on an open set of Racing Beat headers at 9,500 RPM. I hope someone has, because I can't find a good way to test mine without drilling holes in them, which I hesitate to do because I want to sell them.

I cobbed a $30.00 tractor muffler up to the headers in true ghetto ricer fashion (hanging down under the car) so that I could take it for a spin (I am still waiting for the mufflers that I ordered). My initial impression on my butt dyno was that I picked up an immense amount of low-end torque (below 2,000 rpm) over the racing beat headers. 2,000 to 5,000 felt about the same (although the tractor muffler is probably creating significant backpressure by then). I couldn't bear to rev the engine past about 5,000 rpm on the street (rotary engines laugh at the puny sound attenuation of tractor mufflers), so I don't know about the high end.

I am running 0.3 AFR leaner at idle and about 1.2 AFR leaner at 1,500 RPM WOT.
About 0.8 AFR lean at WOT at 2,000 RPM, 0.3 AFR lean at 3,000 RPM, about the same above that.

I suspect that I have my tractor muffler to thank for flow restriction at the higher speeds (choking the headers). I can hardly wait until my new mufflers come in.