I have the same book--its and older one written in conjunction with Hot Rod magazine and called Engine Swapping Tips & Techniques.
That was written a long long time ago and both the V8 swap and diesel engines have come a long way since then.
Since you like the Z I'm assuming that you enjoy performance. Unless the engine you are installing in the Z makes up for its weight in performance, it is not worth doing the swap in my opinion. The Z car is a sports car by nature is best suited to that purpose. That said, if you are looking to do a modern diesel swap, then that is a different animal. Turbo diesels are gaining more and more popularity as they continue to show what they can do at the drag strip and now even at Le Mans. The one obstacle you will have to confront is weight. To my limited knowledge, the readily available diesel V8s are very heavy and most come from trucks. A Mercedes Diesel V8 would be a possible alternative, but very (prohibitively) expensive.
For all your trouble, if you are truly looking to do something different, do a simple V8 swap, turbocharge it, and then convert to propane (LPG).
Davy