We've used boyesen and CR125 reeds. You can more or less put the Stock blaster cage INSIDE of the CR125 cage.
My brother Nate did an article on this i believe.
He got a blaster reed spacer(shoulda got the CR125) and then sanded down the sides of the cr125 cage. Used a dremel to open up the intake manifold and the reed spacer until the cr125 fit inside. It took some time. Grind a little, see if it fits, grind a little see if it fits.. Grind a little... After they fit, make sure they open all the way... lol
I actually did the same with my yt173 3 wheeler... Only the stock cage would fit inside of a blaster cage.. So i upgraded to blaster reeds. Had to make my own spacer and drill own holes for bolting through spacer and reeds... I like them lol.