Bottom line the hardware is garbage. If you use the 7/8 spacers the allen bolts are to short to catch enough of the threads to securely mount to the bars. I'm willing to be that even if you used the 1 1/8 bushings the bolts are to short.
I managed to strip out the bar mount threads using a 1/4 ratchet with an allen socket.
I would not recommend this product to anyone even at the sale price they were offered at.