Our E85 can cause injector black tar..(pics inside)

Correct. Altho your PCM will probably accept a flex fuel tune but you will still need the ethanol content sensor and wire it into your PCM.

I took a few pics of my injectors that I will post up tomorrow. All except for one were all as clean as the day I put them in. One injector had a little corrosion or build up on it but not bad. Definitely no black gunk!