They may be thinking your total package is not streetable. My guess is with the head work, cam and carb they are thinking it would be too radical.
In my opinion it should work with a manual trans and some gear or an at with a decent convertor stall. I am guessing you are talking about 40DCOEs which are infinitely adjustable. There are plenty of books on tuning them; down side is parts (jets, venturis etc) are expensive.
We have had several 1300 and 1600cc Alfas with dual 40 or 45DCOEs and they drove very well. A hot ~4.1 liter six should be fine with three.
