I've dyno tested the SV, the 440-2, the Mopar 337, and the 440-3X back to back on my 514. On my engine the SV, 440-2 (with adapter) and the Mopar 337 all made exactly the same peak power.

I prefer the SV intake since it didn't require an adapter, but the adapters didn't seem to cost any power on my engine.