I agree with the advice that the 11x4' are pushing the envelope.

All of my 46 engines responded to 11x5s like they were too easy to spin. I wound up wanting the 5 pitch enough to cut down 12x5s to 11.25" diameter to put enough load on those engines that they would be happy with the shallow pitch. And truth is, I think a couple of my 46s would like it if I made some 11.5x5s for them.