The 240Z were around 2355+ lbs and started putting on weight from there.
I’ve seen people state that the SBC (iron block) weighs less than a car with an L series. And while looking for a site to quote I found one that says it weighs more. So throw that out the window…
One FAQ concerns the added weight of placing a V8 into the Z. The weight increase is marginal (160 lbs more) with a slight shift of center-of-gravity to the rear, (for the set-back design)
Although I have never seen any info on changing track and suspension goeomety I have seen fender flares filled up, most likely through wide wheels and tires…