The must-have book on Daytonas is fittingly titled Daytona Cobra Coupes, by Pete Brock, Dave Friedman, et al. Published by Stauffer Publishing. Go to
www.staufferclassics.com and click on "Publishing". It appears that you can still order the book directly from them. If not, here is a link to a seller who appears to have at least one used copy available:
www.addall.com/Browse/Detail/0964819309.html
It is not cheap at $100 for the base copy ($400 for the limited edition signed by every surviving Shelby Team member, including several who have passed away in the interim since the book was first published), but it is a huge book that covers every aspect of the cars and contains many, many facts and anecdotes you won't find elsewhere. Highly recommended--
Bob