Where did you come across this piece of wisdom? I'm running Dell 40's, dynotuned and it's running as well as it was when dynoed 2 years ago. I just pipped 8.86L/100km the other day.
These are dellorto's, can't comment on Weber's ability to hold a tune.
No. Value is terrible. Waste your money if you want, but after you spend that, you'll spend another 300 bucks on the dyno. 50 bucks for fuel pressure reg. Plus you really should run a cam and extractors, thats 200-300.
My dellortos on manifold set me back 250, bolted them on and it was driveable. Then 300 for a tune.
2000 is a joke.
48's are unecessarily large, I run 28mm chokes in my 40's and I would like to go up to 32. To hark back evans point about airspeed, Chokes determine the airspeed, not the throat size. Putting a 48mm carb on then running a small choke is a bit ridiculous, you can get good solid performance with 40's, if you were building a serious racecar then you would probably go with 45's so you can keep your options open.
This is for twins.
Might as well go with twins, but yeh you could run a single 45/48 I suppose.
Mine is on a worked 5K with a big ass cam. It's driveable but that's really because I have a stock flywheel, high idle, small chokes (low down response) and a fairly agricultrural 5K dizzy curve.
I could make more grunt by changing some of those things but it's a daily so I'm happy as it is.