Ebay GT45 + 5.9 Magnum + E85 blow thru

Also having some issues with the FITECH. I logged all of my runs and the AFRs are going really lean under WOT/boost. It's really concerning but the engine ran well, but I won't turn up boost until I understand what's going on. Frustrating. Max boost was briefly about 7.5psi last night.

How lean?
E85 right?

Fuel pressure holding at WOT?
Injector duty cycle no higher than ~85%?