As you can see from the pictures the only port that has any reason able flow would be #1; the rest go directly into a hard 90 degree stop. The originals have the raised letters N I C S O N in an arch over the 3 bolt flange. If I ever build a streeter I would definately use them just for the "cool" factor...JD


216.158 MPH 12-Port 302 GMC on 70% 171.0 MPH 302 stock head on gasoline 7 years later