What you are trying to do is like trying to fit a square peg in a round hole, the 7/8" is 22mm, this will never fit a 1 inch 25.4mm stem.

Would do two things, get a vernier caliper to verify the measurements, and then once confirmed search for 25.4mm handelbars and purchase the stye of this that you like.

Or you could look at replacing the stem with one which would fit your bars, Nitto make nice ones.