Sorry for the tardy response, I have been busy lately. The 1.5KE27CA is bi-directional, so you can hook it up either way. The BYV32E is a dual diode in one package, but you want to use just one. Either one is fine. In reality, any ultrafast and ultrasoft diode will do the trick quite nicely, I just pulled that one out of the supply I swiped the E-Cores from.