Sorry for not getting back to you sooner, Gramps.
You can do the swap legally on your '76 Z if you pull an engine from a '76 V8 Chevy car and all the smog equipment too (PCV, charcoal cannister, smog pump, etc.) The engine compartment will look a bit cluttered, but that's not a big deal. Read about it in the JTR book, if you have not already purchased it, and do it legally to the car you have now. Once you get the car registered legally with the V8, you can then buy smog legal performance parts to hop it up a bit. The car will still be fast and you have the option (it is illegal ) to pull out the smog stuff and reinstall it every two years. The smog pump is really the only thing I personally don't like BTW.
Davy