More original details
My rear suspension arm is off the car now and I can see that it still has the paint markings from the factory. The AB letters means it’s for a 308 GTB and the USA means it’s from a US spec car. Seeing a paint stamp identifiy the type of 308 and the destination market on the suspension arm is a little strange at first, given that the suspension arms are identical between European and USA models.
However, the springs are different on the USA cars; they sit a little higher than the Euro models. At the factory each corner was attached as a one sub-assembly comprising hub, suspension arms, shock absorber and spring. This assembly method meant the entire suspension subassemblies on the production line needed to be different for the North American models.
This is why we see the ‘USA’ stamping on the upper suspension arm, where it is easy to see. It is the same store for the ‘AB’ stamp, the spring rates were for different for those too. The spring rates were softer for the GTS to minimise the effectof removing the roof. So there were different, subsystems for the GTB and GTS models.
Once assembled, these suspension units would have all looked the same. Hence the paint stamps identifying both model and market on the upper arm where it could be quickly read to identify the spring rate and length within the subassembly.
Spring rate variants for the 308: