port size

Im am building a wedge 2 type enclosure for a single kicker cvr 15, the internal cubic feet of the box including the speaker will be 5.07161. I need some help figuring out the proper size for a rectangular port, and the recomended hz to tune the box to, it will be going into an 08 chevy silverado extended cab.

Thanks

Manual gives you dimensions of 3"x 15.5" x 22" long for a 5 cu ft enclosure.  Read all the information.  The port structure, as well as the driver displacement, have to be deducted from gross airspace to arrive at net.  The port grows in length, generally, when you have to accomodate for a shrinking net airspace.  To reduce total port structure, you may reduce the port opening a bit.  This will keep the port from growing too long for the project.