Formula fronts-rear & rears-front caliper clearance?
 

I have '89 Formula wheels with rear 16mm offset.
I'm considering switching fronts to rear, and rears to fronts. My BBK pushes fronts out .3" and a slip-on 5/16 spacer would counteract the 16mm offset (I calculate 15.557mm).
My question concerns caliper clearance when I do this. Will I gain caliper clearance or loose caliper clearance concerning the fronts/rears?

I need to get every bit of caliper clearance. Would I be better off getting another pair of fronts?