No modifications needed to the stock chassis for either part.
The gryo plate adds a spot to securely mount an external gryo when swapping out the stock Traxxas radio system. The plate uses the stock XL5 mounting holes in the chassis, you can use it in between the stock ESC and the chassis, or you can use it on its own when going to aftermarket electronics. The holes are undersized by default to allow screws to thread.
The front shock tower adds a bit more shock position options, the stock tower leaned the front shocks over too much for my liking, this makes them a bit more upright. If using stock shocks you may need to space them forward a little for the short top caps to clear, and the stock shocks may hit the body mount system on the outer most holes.
The author marked this model as their own original creation.