Im not sure that the Lokar throttle cable will have stretched, its more likely that the outer braided sheathing will have compressed or shortened slightly giving the impression that the inner cable has stretched.
And I just re-read the comment too -
...The Lokar is too stiff and it has stretched a coupe of times already and I haven't even driven the car, yet!
When you mean too stiff is that from a routing the cable perspective? I have one of much shorter lenght on another car and it is very smooth and bendy enough. I have the carb facing the single 4bbl way like this -
If you think it would reach I would be interested in the cable if your not going to use it.
Sandy