my first nissan 720 (1985 2 wheel drive, w/turbo) could get over 120mph going up a pass (not average for 720's though)... so it can be done with the z24 in it, depends upon how fast your aiming for? stop light race sure... track prob not. it helps a lot if you slap a turbo on it

killing off the emissions/warm air helps too. but if its a 4x4 over 100 is farther away.
also, clean out/replace the fuel pump filter, most people over look that one (there are 3 filters on a 720... inline tank, pump, & carb)
& make sure you use good plugs and wires, auto-lite is not an option for max performance
p.s. alot of the 80's z series (like the 200zx)performance parts interchange with the 720's z24, not all but quite a few and alot easier to find