Tom most 240z 260z fairlady peeps see the light when they put an LS or windsor with the config you just mentioned as the L6 is usually around 12 lbs heavier than an all cast iron windsor with cast iron heads.

I would love a 1200 coupe with extended front end moving struts or modern aftermarket wishbone setup forward to have a 99inch wheelbase or 10 inches longer than the standard. This will allow a windsor or almost mid mounted L series with Ka24de head to handle like a demon.