slotted port dimensions?

ok, here goes.  i'm not new to car stereo, but i am new to box building.  i'm intending on using a single 12" kenwood exc kfc-xw1202dvc powered by ken exc xxv-03a, inside of a slot loaded enclosure.  i've built the box, hopefully the pics will download properly.  it's a slightly weird shape, so hopefully the pics will explain.  question is, where, and how oriented, and how long should the slot be?  i think i'm wanting it tuned to about 35hz.  i intend on the 12 being mounted on the top of the box, face of speaker facing out, either center, to the left, or to the right.  not sure if putting it to the right, might make use of the extra little pocket, as shown in the pics.  any suggestions on how to finish this box up would be great.  thanks guys!

sorry guys.... not sure what happened with the pics.  i'll try again....

and the second one....

and just in case you can't see the dimenstions....

8" tall on left side.  10" tall on right side.  15" deep.  22" side to side length on back side, and 24" in front.

thanks again for any help