i said i'd post this information once i pulled and stripped the Webers from my 914.6.
late '70s-early '80s AJ Racing (and others, i am sure...) sold a "/6 Power Kit" with a matched set of jets and venturiis that corrected some of the lean stumble that the factory jetting caused - i think the cars were kneecapped a bit for emissions...
anyway - here's what was in my car, an E-cammed otherwise stock 2,0 (both AFAIK -- it's what i was told...)
60 idle
175 air correction
F26 emulsion
35 (!)mm venturiis -- there were of local mfg and *not* Weber parts
i run the tall '906' preatomiser aux venturiis
my car was running megaphone exhaust on the Riverside l-o-n-g course so we had the mains bumped to 145 - i think we ran 130 with the street muffler - mightta been 140. the box with all my loose "spare" Weber jets has yet to resurface after the move...
i don't claim this is the current hot setup with today's gas. it's is a point of historical note, not a specific recommendation.
i will, however, say my car ran GREAT on this setup...
the irony is i just bought a set of 34mm venturiis to use with the 2,7S -- i think i'll put it back together just like this and check it out...