This could be interesting, although I don't know how valuable it might be since so many flat-tops have been scrapped by now.

http://sacramento.craigslist.org/bks/638553825.html

The body of the ad:

Here IS A WONDERFUL AND RARE EXCLUSIVE book. Collectible just for the content. THIS IS A WLL LOVED AND MECHANIC "ADDED" PATINA BOOK. In a three ring binder and obviously useful as it is well used. In great shape with mechanic finger prints all over it. Must be really great. This is a Nisson Motor Corporation August 1975 publication for 1973 240Z and 1974 260Z Fuel System Modification Plus Manual. secion one; modifications, section two; performance, section three; related and section for; toubleshooting. This wonderful book is $55 with $5.00 shipping to anywhere is the USA or free pick up.

Anre,

I got a copy of this book....a great source of info if planning to use flat top carbs, but there is only a few doing so/plan too go with flat tops.

Of all things anyone racing a 260Z in ITS might find it useful.