My first e85 experience.

I run a BLP internal regulator belt drive pump. I have talked to them twice, because of the prime/drive system I just put on. I wanted to make sure I can run a dead head shut off valve (which I got from them. It is also required by NHRA on all belt drive fuel pumps.I got the O.K. you can even pull the shut off at the finish line, so that I can switch to gas to drive back.
They said that all it is doing inside the pump is looping the fuel, no harm done.In their instruction though, it says return fuel line,external regulated fuel pumps are better, but most people run internal by-pass pumps, because they are more simple to hook up.
There may be some confusion,the ball valve we were talking about, is on the fuel cell vent line. A valve to close the system, stopping moister and evaporation, between races.It's a great idea for E85 too.