LD4b 340 Edelbrock Intake

On a mid level performance engine, you won't notice hardly any difference between the LD4B and LD340. If you get real chippy, you could open up the port via gasket matching.

If you have the LD4B already, run it. There are better places to spend money than jumping to a LD340/Perf RPM/Air Gap for a minimal gain if any.