I just wanted to let you all know that this can be done with out any drilling. I was able to put these mud flaps on my slayer only using the RPM slash mud flaps, 2 Revo 3.3 Tie Rods, and Some Heavy duty Zip ties.
Just screw the tie rods into the Slash mud flap mounts. Make sure they go all the way. Then place it in the Stock rear bumper and Zip tie it down. I ran it a few times and It seems to hold up good.
Here are some pics hope they help.