Edelbrock RPM Air-Gap

Here's some manifold heights from various small block intakes

A is the front measurement B is the rear measurement

1971 Stock Themoquad 340 cast iron manifold A 4.0625" B 5.1875"
Edelbrock LD340 A 4.625" B 5.625"
Edelbrock Performer A 4.130" B 5.130"
Edelbrock RPM Air Gap A 4.900" B 5.800"
Edelbrock Performer RPM A 4.900" B 5.800"
Edelbrock Torker 2 A 5.250" B 6.190"
Edelbrock Victor 340 A 4.150" B 5.700"

Hope this helps