A victor jr is a single plane manifold, there going to hurt you more than help, there power range comes at way above a normal driving rpm, I think like 3,500 or 4k. Your gonna want a dual plane manifold, there power range comes in at 1,500 - 2k, Edelbrock Air gaps, performer's, Performer RPM's are all exzamples of dual planes. The diffrence between dual plane and single plane is, if you look at them, a single plane has 1 big hole for the carb, and a dual plane has 2 holes, split down the middle.