Also, putting the old brake pads in the new calipers and putting them in position on the rotor, I had about 1/8th in clearance. Sound about right?
And the pistons are all the way down in these calipers, not extended at all.
Remembering the last time I worked on mine, that sounds about right. The pistons will stop travelling when the pads contact the caliper. They’re designed that way, and it makes for an adjustment-free service life (check fluid and top off as needed). As long as the pad and piston retract enough (not very much, actually) when you let off the brakes to let the wheel turn freely, you’re in business.