Streetmaster to Airgap

Mopar Performance Parts - '71 Satellite 340 Small-Block Bolt-Ons - Hot Rod Magazine

What increase would you expect when going from a streetmaster intake that looks really restrictive to an airgap that's meant to be the best dual plane currently available.

Doesn't look like that little intake manifold was really choking down the performance of that engine.
Looks to me like a good gain for the manifold swap. I wouldn't expect 50 HP though.