This is the first book to get if you are going to work on a 1964-1973 Mustang (and probably the only one you'll ever need). I don't know what some of the highly-negative reviewers on Amazon expected, or how much hands-on auto repair experience they have, but the Hayes Mustang Repair Manual has been the best *general* How-to-do-it, step-by-step manual for these cars since it was first published back in the early 1970's. It has stayed in print since then because a million Mustang owners have found it invaluable over the past 46 years. Sure, the engine-rebuilding section is slim -- it's for people who already know how to rebuild an engine, but it is complete. If you don't know how to rebuild an engine then you really need a task-specific manual devoted to rebuilding the particular engine you're working on -- don't expect a general whole-car tune-up and repair manual like this to give you more than an overview of something so complex as an engine rebuild. I don't know why the person who couldn't identify his carburetor parts with this book had a problem -- there are full page diagrams of how each part of the several different factory carbs go together in here -- maybe he had an after-market carb, which wouldn't be covered since the Hayes manual covers the cars as they came from the factory. Duh.
I've owned 6 Mustangs from the 1960's and this book has been all I've ever needed to keep them on the road. And, yes, I rebuilt my 1968's 289 V8 using nothing but this book. I actually have two copies, one in the trunk and one in the house. This manual is the best place for anyone working on an old Mustang to start. If it turns out it doesn't quite give you all you need for what you're doing, then you can go looking for a task-specific manual or ask around on the internet forums. But I always check my Hayes manual first and rarely have to look elsewhere for my answers.