what do u mean by fully counter weighted? and it is! took it all apart and took it to an engine shop and they said its bored 40 over with 280z flat top pistons
and why move it? it has headers already and it was left in the same place
The crank in the pic shows that it has counterweights on only half of the crank throws. The early L18 cranks had counterweights on all of the crank throws. It makes for a smoother running engine.
I can't tell from the pic, but in most cases, those Z blocks had an angled pad of material on which the ID was stamped, and the angle makes it impossible to fit a header (without mods). If you say that it does fit, then ok.
Why move the dipstick? For easier access and a more appropriate appearance. L motors had them on the pass (right) side.