OLDER EDELBROCK PERFORMER INTAKE POTENTIAL ON A 340
In my opinion, the "plain" Edelbrock Performer won't be any better than an early OEM TQ intake even in stock applications but it saves weight. The RPM & Air-Gap would likely be a step up and both are identical internally. Downside there is that any adapters being used to go from square to spread bore normally result in a flow reduction.
Here is a dyno test article, but no OEM spread bore intake.
Small block intake dyno test.
(Gotta look at the #'s through the operating range, not peak numbers.)