Too hot of a plug??

[Super73]

Well, I fixed my oiling issue, was pulling oil through the intake with the stock cranck case ventalation and the big ring gap/blow by. It was really hard to read a plug before.

Put new plugs in it today and went for a quick 7-8 mile ride, standing on it once. Here is what the plug looks like that I pulled. Wide band reports AFR is pretty much dead on.

Keep in mind I am on E48 (50/50 mix of 91 and E85). Part throtlle / idle I have a bit leaner than stoich. but look at where the heat mark is at. looks to me like a TR6 is quite a bit too warm for it even on motor.