I don't know about the 34 DGEC but I did have a 32/32 DGV (progressive, just a smaller secondary bore) on my 79 for quite a while. I did not really notice any real big difference when I put a 32/36 on it instead.
If you really want a good answer try emailing weber and asking. In my experience they are pretty good with the technical questions, and can even help suggest jetting depending on the details of your engine build over stock. Just browsing around the site I wasn't even able to tell for certain if the 34 DGEC is progressive or what.
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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)
MEPR: Man, my 4x4 makes all other LUVs look good
