Im going to give it my thought's,
I'm very happy with my Z if I had the chance to start over I would do it again and again.My brother bought a 240Z to do the same but got disapointed on how louder it is over the Z and other differences.Don't get me wrong we are used to 280Z's I guess.The 240Z has a lighter body and the addvantage of not requiring smog......Well since I own the 280Z and know how long and how much,I told him not to start this project due to being similar as mine.I told him to get something else like a 04 ZO6 or something similar add some kind of boost,set up the suspencion and enjoy it....
I'm thinking about buying a modern sports car after the Z is done,I want all the gooddies from today, even though you can run a cruise control,Navigation system on your old Z its always going to feel different...
So I think I just said have them both....lol
Edit:I drive traffic speed and I pulled on a C6 not long ago.....