Who does custom sub boxes
 

Who should I go with for a custom ported box for my 2004 f150.

JL Stealthbox box if you can still find them. Amazing boxes.

And amazingly overpriced.

Go check out your local car audio shops (not best buy). Any competent car audio shop can build a box with the proper airspace for your sub that is ported and tuned correctly. Price wise just depends on your area, box size, and where you want it mounted (i.e. if you want to try to fit it under the seat that requires a lot more labor than just a standard rectangular enclosure).

I like my fox acoustic box......They do one for the 04 also.. foxacoustics.com

I'm having Robert King of cherryman custom enclosures build me a ported box for 2 sundown sa 8v3s.