[Chipper Chapman]

In recent times small journal blocks (327) have become very hard to find. (at least up here in frostbackistan) It states you can use a large journal block with spacers, or thick bearings, but again those spacers and bearings have become unobtainable. Is there any reason you can't use a large journal block and crank since it really isn't a performance advantage? As I understand the rules only state how far you can undercut the crank?
Thanks