Will these fit?

Probably not. They will most likely bolt right to the pegs, but you will need to make top mounting brackets, just like stock YFZ Heel Guards
 
I would just get full nerf bars! Although on my blaster the actual fender is different lengths on the part where the heel gaurd will bolt on... So, I don't think they will, although I am probably wrong, I had heel gaurds, then a piece broke so I had to take them off D:
 
I doubt they will fit. Like said above, just get the full nerfs with the heel guards built in.