COX vs NORVEL plugs and head clamp

I know there are several NORVEL owners who are regular posters here, so this may be of interest. This is not a competition, but just a head to head comparison of the two plugs and head clamps. All measuraments are in inches.

...........................COX..............NORVEL
plug body dia.------.335------------.334
plug flange dia.-----.497------------.496
flange thickness----.056------------.051
filament hole dia.---.113------------.132
head clamp dia-----.746------------.746 (AAN)---.864 (Revlite) The Revlite head and cylinder are significantly larger
head clamp ID------.347------------.337 This is the hole size for the plug

Both clamps have 3 fins; the COX fins are the same diameter, the NORVEL bottom fin is slightly larger than the top two.
The NORVEL fins are slightly thicker than the COX fins.
The wire diameter of the NORVEL filament appears slightly larger than the COX filament wire diameter.
The filament coil diameter in the NORVEL plug is larger and wound more uniformly than the COX filament.
The NORVEL filament appears to be swaged into a slot in the plug body; the COX filament is spot welded.
Plugs and head clamps will interchange, but the COX clamp is small compared to the Revlite clamp. Thread pitch and diameter are the same for both.
The NORVEL center post is held with a swaged metal ring; the COX plug has a color coded insulator.
The COX plugs are available in hot and medium heat ranges ($5.95 USD from COX International). The NORVEL plug does not have a heat range listed ($7.95 USD from NV Engines)

The top two images below are from the COX International web site; the NORVEL plug image was downloaded from the NV Engines site.

I do not have any performance figures between the two at this time.

andrew