[Rick Parker]

There are trade-offs to manifold design. The Victor Jr manifold is a single plane open plenum design and will develop more HP, however that HP will be up the RPM scale a little further than with a dual plane Air gap Design. A dual plane will generally have a little better distribution at lower speeds due to the smaller cross section of the port runners. The dual plane is a little more flexable and will provide more torque at a lower RPM but looses out to the Victor Jr as the RPMs rise. The open plenun of the Victor JR will support more airflow at higher speed but the fuel will tend to fall out of suspension as rpms drop (at part throttle) and therefore at low speed has poor fuel distibution and an irradic idle.