Why does Shelby like the number 98 so much?

[Historybuff]

If you look at various race cars raced by Shelby, from Ferraris to Maseratis to later on Cobras that he fielded (including the small block raced by Miles) the predominent choice in numbers for the roundel was 98.

So I was wondering if he has revealed in an interview why he likes that number? I wonder how far back it goes--what year he first ran a car with 98 on it?

I heard race car drives are superstitious , some having a pair of lucky driving gloves, a lucky helmet, etc. I guess having this number on his car has always been his thing.

I don't know if race organizers like having a team come with their own choice of numbers but it seems in an amazing amount of races he was able to have no. 98.