1974 IROC/RSR production question

[Kaleid]

While reading up on details of the 74 Euro Carrera, I came across some info on 1974 production data and noticed that aside from the RSR cars, there were a handful (15?) of IROC cars made (delivered to Penske I believe). The VIN number range on the IROC cars seem to be the same as the Euro Carrera range- 911460xxxx. Were these cars simply pulled off the assembly line randomly and made IROC-spec cars? Just curious why these IROC car VINs are seemingly random (there is probably no answer for this), but more importantly, why weren't these cars designated as a different VIN type like the RSR cars (911469xxxx)?

Thanks,
Marco

[davep]

The cars may have random VIN's, but the production numbers are nearly sequential. To me that means the bodies were constructed one after the other in a block, and set aside. I believe the bodies are unique since the rear torsion tube was different from the others. So when the bodies were completed into a finished car, then they might have been returned to the production line to get their VIN's, just one at a time.

[72targa]

http://www.pbase.com/slidevalve911rs...tory_cars_iroc