can anyone give me some clues on setting up my webber (venturies, jets, screw adjustment)

dncf 40
TP1600
pointless 009
gt40 coil
empi monza pipes

http://www.redlineweber.com/html/Tech/Table_of_contents.htm 

and

http://www.aircooled.net/gnrlsite/resource/articles.htm 

Rough rules of thum

Main Jet is 4.1 x venturi
Air is main + 50
Idle is whatever "best lean" is - nothing else

Venturi is approx you inlet valve less a bit or even equal

Venturi moves power up and down the rev range.
32 vent makes power at higher revs than 28

A stock 35/32 valved head should have 32 vents. A 40/35 head 36 vents

For example - MY engine
Stock heads = 32 vents
4.1 x 32 = 131. = i am running 130 mains
Add 50 and my airs are 180

Idles. For "some" reason all the reading you do says idles should be 50 - 55.
I ran 50's and it backed fired. I have 40's in there at the moment and "best lean" is 1 1/2 - 2 turns out. I will play over Xmas and see if i can tune at least some 45's in there or maybe 50's if i cahnge E's

Emulsion Tubes = Black Art
NO rhyme or reason with these that i know of
99% of people say F11's for IDFs.

My Alfa IDF's came with F57's and i know people who say F2's will fatten up your idle jet.
I need to get my idle fatter as the 40 works well but tends to clog.

This is for dual 2bbls not a single situation.
Singles are harder to set up but generally about a size or 2 larger on things

Sounds like similar setup to mine although I have mild cam.
I run 60 idles, 140 mains, 200 airs. Make sure your timing is about 30 adv at 3000+rpm. Set idle at about 850 - 900rpm. Screw in mixture until engine starts to stumble, then out again about 1.5 - 1.75 turns. Don't know much about venturis (take heed of Blue). I note you have a GT40 coil and pointless 009 - does this mean you have a compufire or pertronix fitted? I'm arranging to get one courtesy of BuggyBrad and was wondering if the GT40 has a ballast resistor in it or have you done something external? (I know nothing about this stuff but am trying to find out).

will adjusting those screws 1.5 turns make my fuel economy worse.

the main reason for looking at it is poor econmy. having said that i want get up and go when i put my foot down

i currently get around 9 k/l

Not too sure what fuel economy I get but it is still pretty p poor. Mixtures probably more likely to end up nearly two turns out than 1.5 - I just mess with them until the revs are at about the "right" spot - nice, clean sounding (it does seem to make a difference with economy, but not huge). Good luck