[DonC]

Well, that didn’t work.
Put the silicon spots on the pads so they’d be inside the pistons and added CRC orange compound around the periphery of the area outside the silicon.
Did the 40 grit flat sand of the pads and a light 220 grit sand of the disks to break up any glaze that had developed even though visual inspection didn’t show any (4300 total miles on the car)
Put the whole thing back together with only one help call to Bob about the spacers on the passenger’s side caliper and road tested.
Same results. Hard braking is noiseless and very good. Light braking, as in town driving stopping for traffic lights and stop signs, results in significant squeal.
Things I noticed while doing the mods is that the piston edges had actually worn depressions in the Wilwood shims. Not complete circles but top and bottom about a 50-degree arc.
Next try will be to remove the Wilwood shims and try just the CRC compound on the bare pad backing plates. If that doesn’t work I’ll be looking a different pads.
On the plus side, the next time I drop the calipers I’m going to drill the bolt heads for safety wire which I’ve always done with all of my brakes in the past.
Will let you know what happens.
DonC