So, chucked a pair of the Speedway stamped steel hats (both out of the bag, unmolested spares) on the lathe at work today for 5 minutes, found the following:
(actual mfr unknown, probably Allstar, they also make stamped hats, Speedway doesn't really make anything )
They were ~identical, and the rotor bolt holes were in the noise precise, dia and relative to outer edge.
That's the extent of the good news.
Axial to outer lip .012” tir
Axial to center of holes (ignoring stamp flash) .007 tir (if outer lip was same it would be passable)
Holes dia +/- .002
Rotor flange holes to outer edge (at surface) +/- .002
Rotor flange holes radial to outer edge/flange TIR .035.
Radial at hub flange shoulder TIR .025
The centering/register hole is off center ~ .025” from everything else
The register hole ALSO varies from round by .015” , 3.060-3.075” (3.060 is spec size.)
These stamped steel hats are not fit for purpose.
Basically, rotor bolt hole circle would be ~.025" radial runout with these particular stamped hats
The ones on the car seem to be about the same, but was not able to eliminate all variables on the car.
There is a small amount of play in the bolts<>holes so you might
be able to cut it to ~.009” radial,(Wilwood max spec)
…if you could install/adjust/tighten rotor to hat on the lathe with dial indicator.
The axial runout is still effectively 2X total rotor spec, even after deburring/lapping flat, even assuming the radial runout could be brought in, and if the rotor itself was perfect... it's still whack.
Will be trying Smileys Racing Products Coleman-spun steel hats Friday.
If those check out reasonably, I'll run them, if not, they get returned and I order something cast or billet, but machined.
These are round, so it should not be rocket science if they get spat out of a CNC machine by the dozen.
Speedway will be getting an email...