[V8] More rear brakes...

[Gunter Lorberg]

I also have a question about rear brakes....it just so happens that I'm changing the pads.
 
I am starting off with calipers that have had their pistons returned inwards to their 'starting' position (a good used replacement set....I think that the original calipers were not moving as freely as one would expect)  When I reassembled the brakes using the new pads, there was still some degree of 'free play'.  I have not yet touched the brake pedal.
 
My question is:  Will the rear calipers/pistons immediately accomodate by moving inwards (let's say at least an eigth of an inch) to the new brake pad thickness when I finally stand on the brakes OR do I need to manually readjust the pistons outwards (if that's even possible) until there is virtually no 'play' there?
 
Thanks...(I really appreciate the help I have received online.........couldn't own two of these unique vehicles without your help)
 
Gunter Lorberg
(2) 1990 Canadian V8s