I think Clifford sells a 2 bbl water heated intake. It's pricey though. Somewhere between $275-$300 as I recall.
I think you may be wasting your money on the adapter and 2 bbl. Like Fred said in your other post, the airflow with the stock intake and adapter won't be any good. I can't say for sure as I never tried it. I did try several variations of Rochester 2G's on my Offenhauser 4 bbl intake. Used an adapter. I tried and tried to get things to run right but, always had the same result: CRAP! I installed a small Holley 4 bbl (450cfm) and it's been good.
If you're not in hurry, my advice is buy a new intake and then keep an eye out for a used 390cfm Holley 4 bbl. Buy a rebuild kit. Fabricate some linkage (which you'd have to do even if you went with a 2 bbl) and you're off.
-David


Tradin' up dimes for nickels...
'`'`'`'`'`'`
My \'65 Chevy C-20