Aussie CRT X2

Very nice build ...I'm in the process of converting a CRT-x1 truggy...my first conversion......I have the stock tire/wheel combo ..my tires seem a lot wider then yours ,what tire/wheel combo are you running ? i would like to go to the narrower tire like yours....i was afraid to notch my motor mount (same mount as yours ) as i didnt want to weaken it any ,does it seem ok with the notch ?...thank you for the help and any advice ....