13B air pump question

Hi ... I've got an 84 GSL-SE w/ original 13b & i want to upgrade my intake to a K&N style cone. i read that some 13b's use the air pump to actuate 5 & 6 ports & some use back pressure. does anybody know what is the case w/ the 84? right now the car is running great w/o the air pump belt installed & no cats, just a straight pipe to the muffler. i just want to make sure i'm not missing out on more performance. thanks.

As far as I know, it's the 13B in the FC's (series 5) that need the airpump to actuate the 5 & 6 ports. I do not know if this is the case of the 13B that was available on the FB's.