My only guess was to sell more books. I read the forward thinking it would say to follow the guidance for a 52 ,etc. but it does not make any mention of this, however it alleges that the book covers 48-53. So far I have not found a single reference for a 53 in the book in the sections I was looking in for info. I read some threads on this site where folks mentioned finding a shop manual for a 53 was like finding hens teeth. Frustrating.
Deegs