I just finished converting my Twin Spark motor from Weber 45s and a distributor from autocomponenti.com to motorcycle throttle bodies and an ecu from DTA.
It starts great ,idles at 850 rpm, goes like mad, make no black smoke, is much better on gas and I do not have to mess with jets any more.
Here is a link to my photo page Picasa Web Albums - Alfa Dave - Alfa Twin Spa...
It was a lot of work but I am glad I did it. When I put the TS in my car I wanted things to be simple so I went with Carbs and the distributor . I was so wrong. Tuning webers for a custom setup is a huge pain and you can't do much with a distrubtor. To control the VVT I got an rpm switch but I never got around to installing it. And to bring on my electric fan I put in a temp switch.If you are going to the trouble of an engine conversion leave the Carbs and Distributor and all the rest in the past .
Now I have full control of fuel and ignition I also have a rev limiter and fan control. I have not set it up yet but the computer can also control the VVT.
For a full on race setup Webers would be fine maybe even better but for a daily drive use the Bosch or an after market ECU.
alfettaparts what 105 car do you want to put the TS in? If it's a spider it's very hard to get the Alfa intake under the hood.
In closing (here it comes) I wish people on this board would not tell others to "use the search function better!" first it's rude and second the search does not work very well. Someone could make a sticky for the Twin Spark conversion info . That would help reduce the number of times the same questions get asked but why ? It's not like asking a question again will kill a tree or something. (done venting)