Does anyone know if the Alco 251 or EMD 645 schools have minimum rank to attend?

I went to EMD 645 when I was a Third so I don't think so about that one.

when you do your training request it should say what the minimum rank is to attend the school. i know for ALCO 251 it was E-5 but you could get in as an E-4 with either a waiver or command endorsement. Hope this helps.