Hub and disc assy doesnt go back far enough

I am in dire need of assistance as I have changed my bearings and repacked
the hub with grease and trying to install the disc assembley back onto the
stub axle, but it seems as though it is not going back far enough to allow
the calipers to fit on.

The car is a FJ40 Landcruiser 1976 and I am installing a FJ60 disc brake
assembley and swivel hub.

I have measured the bearings, they are the same sizes (as the old ones), I
have checked the gaskets between the swivel hub and rotor backing plate -
but, it seems to need to go back about 5mm for the calipers to line up
correctly.... the only thing I can think of is maybe putting it all on the
car and just tightening the hell out of the locking nut in the hope that it
will compress the seals or something....??

Any ideas would be GREATLY appreciated - thanks very much in advance...

Wortho.