I heard that the 79 intakes are better than the other years 80-85, Why is this? can some one tell me this. thanks

 

No shutter valve.

 

what's a shutter valve

 

They are better cause they have less restrictions in the flowpath in the runners. As time went on, Mazda added more and more emissions controls to the car, causing more bumps and obstructions to smooth airflow in the intake runners.

A shutter valve was on late model FB's. Its a butterfly in the #2 rotor primary intake runner that shut off flow to the rotor under certain conditions.