You can go with a shorter BB spinder to bring your cranks in.

On a related note, about two weeks ago my BMX cranks got trashed so I moved over some old road cranks which have a MUCH tighter Q. However it seems like I'm unable to generate as much power as I did on my old cranks. Has anyone else noticed this. Is it a result of the narrowed stance? The old ones were probably a little too wide for ultimate comfort. Would I be better served by a more modern road double crank?