yes I am using the 45t spur with a 15t pinion on my medusa 1600 on 5s. Runs really good so far, only had the setup for a month or so. I also heard the kyosho 46t plastic spur fits with little to no modification.
You can bump up your center diff off the chassis, open the spur slot, and lengthen your drivetrain if you are really set on the larger spur. GL.
HopMeUp is my friend, RcBoyz is the devil.
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