difference in years

Z31 wikipedia

The 3.0 L (2960 cc) VG30E produced 153 hp (114 kW) and 182 ft·lbf (247 N·m). Bore is 3.43 in (87 mm) and stroke is 3.27 in (83 mm). In 300ZX form, it produced 160 hp (120 kW) and 173 lb·ft (235 N·m). On April 1987 the "W" series VG30 was released, adding 5 horsepower but leaving torque unchanged. In 1989, the Maxima received the 160 hp (120 kW) rating, but also used a variable intake plenum improving torque to 182 lb·ft (247 N·m) @3200 rpm.

3.90, and 3.70.

W-series engines (4/87-89) have full floating wrist pins, versus pressed in wrist pins of A/B series engines. This is the only internal change that would cause any difference, but it'd be minimal, except turbo cars bumped compression from 7.8:1 to 8.3:1 in 1988, but then also ran a smaller turbo at less boost.

oh crap I forgot all about the w series engine.

LOL thanks. I havent tried hard enough but I wanted to see if the difference in the rear gear ratios made a difference in the quarter mile for the NA.

I just learned that the 240sx that shares the same transmission as us, came stock with like a 4.08 gear ratio.

…Im not trying to do anything here just getting some general knowledge =0

Only the turbo cars had the power difference.