Those you have shown above are for a 7.25 axle, not a 8.75 axle. Heres pix of shock plates needed for the 8.75 axle. 2 different stampings both for 8.75.
Proper measurement to determine the width for the U bolts is inboard edge of hole to inboard edge of hole directly across. Not center of hole to center of hole.This will give you a dimension of 2.50" on yours, and 3.0" on the ones i have pix of. You are measureing for width between thr U bolt not center to center of u bolt.
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