Performer RPM vs Performer 318/360 Intake Manifold
Yes there are significant differences. The original Performer was for a power from idle to 5500 RPM, While the Performer RPM was from 1500 to 6500.
For a mild 318, the performer is a nice manifold. I put one on a '72 318 and it performed (no pun intended) very nice.
http://www.edelbrock.com/automotive_new/mc/manifolds/chrysler/chrysler.shtml
Regards,
Joe Dokes