The brackets for the Delco alternators are slightly different. You can address this by either buying a Delco made specifically to replace the Motorola (look online), or by minor machining on the case of the Delco alternator.
You could buy a 10SI for a Jeep application, like a '76 with a 258. You'd still need to hack the case some. I think you drill out the bolt hole a bit and maybe cut off some of the length of the mounting boss. Search online - someone must have covered it. https://www.rockauto.com/en/catalog/jeep,1976,cherokee,4.2l+258cid+l6,1179266,electric al,alternator+/+generator,2412
It's very easy to turn the case ("clock the case") to whatever angle you want. Use a toothpick to hold back the brushes when you put the case halves back together. There's a hole specifically for this.
You could also use the Motorola. It's a pretty bad alternator though - the diodes in them fail a lot. You'd also need to put the external voltage regulator back.
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination ATs, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
ECO Green: '15 FCA Jeep Cherokee KL Trailhawk