So as an autocrosser who will be building a PMO'd shortstroke 3.2 this winter, what is the advantage of this design over the flipped flange 993 header that Ben was converting for heat just a few months back?

My understanding is my current SSIs will give up some top end power but still have a better mid range than the 993 arrangement. Are these an all out race design for track cars driven on the street? Just how do these differ?

what is back purging?

and.... how are these things coming?

Back purging is using inert gas such as argon to purge the weld area of oxygen and other gases you don't want around the weld area and creats a bead that looks just like the outside weld.

and they are coming along well. Brian is taking pre orders I believe.

What are the consequences of the primary length chosen? What kind of N/A motors would these be best suited for? This looks like a great product. Count me amongst those interested.

If a test car is needed, i'm always open to diddling around with exhaust stuff on my car. I could dyno them on a DynoJet 248 against a George's/OBX shorty header setup on my car that's currently equipped with the muffler extensions and Ben's shorty mufflers

The length of the primaries is critical and it helps to determine where the usable power band is in the rpm range. Shorter primaries will produce power at higher rpms and the headers work in conjunction with the intake and cams in producing a nice flat torque curve. Having significantly shorter primaries could upset the balance and cause the power band to move above the rpms most 911 engines are capable of turning. Do you plan to run dyno tests on this header configuration?