Here you go. Green is the bandpass, purple is a single speaker in .4ft^3 @35hz (just as a comparison, two in .8ft^3 would just be graphed as 3dB louder).
Look really peaky, but cabin gain should fill in the low end nicely. Should be stupid loud for a single 8".
Is is a single cab? I would probably do port back/sideways instead of up, if for no other reason than to avoid dropping stuff in it, lol. Also might load/couple better.