I recently bought a Crown Graphic and a Speed graphic. The Crown has the spring back, the speed graphic has a not as nice looking back. And Im considering to switch the backs of them. Since I do prefer the Speed graphic over all.

Is there something that will mess up by switching them? (Apart for the focal plane shutter flash sync thingie that is).

Regards,
Daniel

The service manual for the pre 55 Pacemaker list 4 different back part number sets; 4 for the Speed and 4 for the Crown.
The Top Rangefinder service manual http://www.southbristolviews.com/pics/Graphic/manual-pdf/servicemanual.pdf
list one part number for each the Speed and one for the Crown.

The Crown back will probably interfere with the focal plane shutter if used on a Speed.