1969 Barracuda Fastback

Hawk and Qkcuda, thanks for the input, good to know that I am not the only one who experienced this problem. Counting the numbers or measuring the threaded distance on the bolts is definitely an idea. I also thought about going the easy way and just measure the distance on the wheel lips, but I am concerned about the accuracy of this method.
I am aware that a classic car is not built with the precision of a Swiss watch, but still, I want to stay at least within the tolerances provided by Plymouth - whenever it is possible.