DeTom,
I don't believe the Holley installed in your car is an aftermarket version, yours was installed oem, as your Pantera was originally a European delivery. At some point, the Autolite carbs were replaced by Holleys as oem equipment for the European Panteras. My best guess is that the Holley became one of the standard upgrades for the GTS models.
your friend on the DTBB
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