motor mount issues

[DwightSchrute]

i'm using Mike's motor mount on all my 8ights. they're great, but reciently, i've been having some issues with the motor coming loose when landing a big jump. so much so, i stripped out 2 of the motor holes yesterday. is there anything i can do to prevent this?

i was thinking about getting Mike's front motor spacer, but it looks like he's using 4mm screws on it. aren't the castle/neu holes 3mm? would i then have to re-tap the motor, cause i've never done that, and am really hesitant to try. are there any solutions i'm missing? do you guys threadlock your screws?