Whoa claych, you have been a busy fellow indeed. I found a variant of the 34DAT was used on 2.5 L rover engines but the interesting thing about the one I saw on a site was the progressive linkage between the primary and secondary was adjustable. So you could fiddle with the overlap to alter the midrange power band (I looked at the set up on the 34DATA I picked up and thought about whether or not I could modify the overlap and it seems Weber beat me to it! lol) The Weber guide by Pat Braden suggests that changing emulsion tubes will have a near unnoticeable effect on the operation of the carb as it will be very subtle but it will depend on the main and air jetting totals.

p.s. I have gotten in touch with the webmaster in regards to my inability to post pics so, in the meantime I'll be forced to use links to my album.

...a days work of messing with linkages and comparing 3 different models of carb got me to this point - (start from this link and follow descriptions on each image through the album) http://i1089.photobucket.com/albums/...pspuw5ouuo.jpg

warning - I engage in acts of random madness