Running the Holley's sideways has one or two benifits depending on your bowl configuration. Center pivot bowls were designed for road racing and are affected more by acceleration. They are also longer so clearance is an issue. Secondaries on both designs can starve the jets under hard acceleration without jet extensions unless they are turned sideways. Side pivot bowls are superior performers in straight line use.
In either configurtion bowl vent baffles and or vent tube extensions are needed to be sure no spillover boggs you down.
Now about the single carb rant and TR nay sayers:
There is such a thing as a single 4 bbl tunnel ram. I ran one on a big block Demon with a Thermoquad that my wife drove to work daily. She was challeged often but never beaten. The tunnel ram setups typically gain 1/2 second on most warmed up engines if CFM is appropriate.I have both Offy and Weiand. The setup I like alot is two 6425 650 two barrels on a 2-4 top. They are converted to side pivot bowls and provide better fuel distribution than a dominator on a single plane. Something again not considered by the armchair tunnel ram experts. :)
The larger plenum cloud at shutdown will condense and will require more frequent oil changes.
