Dyno'd the Magnum.

Edelbrock has some core shift issues. With heads and intakes. But the Crosswind is a cheap *** intake, nothing more. You can bolt a 2bbl on a strong engine and it will run strong. But not AS strong as a 4bbl. The facts are the Crosswind is cheap, and has the dual pattern for the money, which is why they get used a lot. It has nothing to do with peformance. The RPM will crush it every time. I have run both, I won't save the cash on a Crosswind any more. A lot comes down to "good enough". If it's affordable and runs strong and well enough for the owner/builder, and doesnt leak, great. For me, they leak due to porosity, They are not cast well, they don't fit well, the threaded holes have to be tapped, they also have core shift, and once you do get them on and sealed and running, the RPM will make more power. Generally requiring jetting changes just due to more air getting thru them. Doubt all you want. Require proof all you want. If you want a back to back test, those that run them, buy an RPM and see what it does for you. If I didn't see it, I might doubt too.
An engine that picks up power going from a single pane to a dual plane had the wrong intake on it initially anyway.