The 390s are going to run too lean. 450s just barely cut it on my 5.0 that I had the tunnel ram on. The idle circuits are just too lean on the 390s.
There was ice on your Offy because you had a fuel leak in one or both of your carbs. Fuel is a coolant. With a tunnel ram, the cooling effect is greatly increased. You were running rich.
If you want show without go, then run a tunnel ram on the street. I think it is cooler to have a faster car than it is to have a poser car.