The tall power valve is two-stage, and the short one is one stage. There is a deep cover for the 2-stage valve. I'd say you have the wrong kit for that carb. Too bad - the sellers charge a premium of about $20 for the 2-stage valve. Possible you have a kit for a 2150, which has a different style of choke pulloff that's not rebuildable. A 2100 kit should include that diaphragm, in my experience. The 2100 came with both 1-stage (early) and 2-stage (later) valves, in my experience. My J10 has a '76 1.08 2100 with a 2-stage valve from a California 360 Cherokee, so the change in power valve brackets your year.
I don't think there's any difference in the activation of the 2-stage vs the 1-stage PV. In both cases, vacuum is applied to the cover area. With the 2150, the cover has a vacuum nipple, and the 2100 as an internal passage to the cover.
Apparently the QuickFuel power valves will fit a Motorcraft. The new valve should come with a gasket. https://www.summitracing.com/search/bra ... wer-valves
RockAuto has the choke pulloff diaphragm https://www.rockauto.com/en/catalog/jee ... l+off,6000
Napa should have it too.
You could try a kit for a '72 V8 CJ-5 or a '71 V8 Wagoneer and it should match the earlier 2100 characteristics. Apparently the Hygrade kit does not include the pulloff diaphragm - that's cheesy https://www.rockauto.com/en/catalog/jee ... r+kit,5964
Should be a good kit otherwise.
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 FCA Jeep Cherokee KL Trailhawk, ECO Green