Thanks for the update!!!
I feel your pain. I have been down this road too, all I can say is don't give up and realize even a failure can be very valuable information for the future. You won't know if something works until you try it.
I think your next step with the head upgrade will solve the detonation problem.
Also are you measuring the E85 alcohol strength. I have been burned a few times with pump E85 being as low as E65. It cost me a engine.
Anyway keep us informed on how it goes.
