Cherokee Drums on 8.75”

Your original sbp drums will not work with the Yukon axles. Even if you redrill the drums, the center register is a different diameter. And then if you have the center hole bored out, the distance that the new axle flanges extend out from the housing flanges is different than your old axles, which is why you need different backing plates and drums.
The Cherokee drums theoretically would fit if you drill the backing plates for the 6 o'clock stud of the axle housing flange, but why? Cherokees only had 9" and 10" drums available; and that's equal or worse than your original setup. The Grand Cherokee used 10" drums or the disc setup. All will require modifications to the parking brake cables and backing plates/caliper mounts. Since any of these would require basically require the same mods, the smart money is on just scoring the G.C. (or Liberty) rear discs and be done with it- same amount of work, but better overall brakes.
Or just get the drum brakes off any B, C body or early half ton truck with the 4.5 bolt circle and bolt 'em on, no mods whatsoever.