Mike S,
Very much appreciate hearing your experiences. Interesting question Wilwoods equivalent pad to Sierra. I suspect there might not be one with exact properties because Bob supplied Sierra pads when I bought the brake kit from ERA, not Wilwoods. I believe they're on Chuck's car, DonC's and pal ERA-FIA's as well. BTW, I'm using Permatex dark green brake pad lube and it holds up to heat well. Appreciate your track testing results.
These Sierras have stopped beautifully, both street (when warmed somewhat) and track, without fade. The shim kit stopped the noise until the day I posted, which makes no sense. Unless your excellent point about warping the backings happened. Vocal chords is a good analogy. However, the brakes performed normally and powerfully shortly after and in stop/go traffic. Hard pedal and no pulsing.
Chuck,
Agree about the piston wall thickness but I got full circle contact on pad backs (before shims) but haven't seen the shims just yet.
My plan now is to tear-down when Bob has a result or product to work with. Then I'll see if the pad backs warped as Mike said or if I'm making sushi out of the shims.
Bob's a great engineer and I have faith he'll find a good solution for all of us.
Very glad to hear from you guys.