The single spring plate and the <85 944 adjustable ones measured .163"
The dual spring plate blades measure: ... .163" each.
Makes sense, they probably had a million spring plates made at a time, so use 2 of the same blade for the duals.
Unless someone is in need of dual spring plates their fate is sealed.
Will check if they are welded on both sides and fix as needed.
I was doing the numbers today on going coil over (purely as an exersize of course

) using the relocated/adjustable inner pickup idea and attaching the front Heim joint ~2" higher for anti-squat like later Porsches used.(inner would need to adjust to match)
Bilstein SG small dia 6" stroke coil over ready shocks look about perfect, 90 ea retail, and the coil over spring mounts/threaded tube bits for them are only ~$40, 2" springs $55-80 ea and the damping settings is available in a huge range, linear or digressive.
Throw in the rear height adjuster... (still haven't figured out which one will work on a T3 torsion)
...and make the heim joint spring plates, as the ones sold look iffy to me, and they are thick in the wrong place....
Rather use German steel (perhaps the blade I cut off)
So <~$600 for
real coil overs and an easily adjustable (height, toe and caster, as well as anti-squat) rear suspension with improved geometry, unlike the $$$$ Mendeola rear setup. Tubular trailing arms in 0/0 would take it to about a grand even.
... Fully weld the rear arm shock mounts and add fabbed kafer bar and set upper shock mount for double shear, i suspect the fabricated steel T3 shock mounts are stronger than the cast unit on T1s, and can easily be reinforced.
Glad I don't race it, that sound like a busy weekend.
I still don't understand why coil over kits cost $thousands.
Rebuildable Bilsteins only cost a little more, but I think are all 2".
I suspect its just going to get the SACO delrin bushings. Maybe.
May have to see how those Bilsteins would fit to replace my current Monroes with the 4-ways.