There are 4 adjustments on the Z hood (240Z-280Z).
Generally speaking, the easiest way to align the hood is to first do the fenders. The fenders bend a lot over the run from fore to aft. Loosen the 10mm bolts and screws to bend the fender lip up or down to match the curve of the hood. After this is done, align the hood. The simplest adjustment is to close the hood and reach through the grill with a ratchet and loosen the bolts. Push down on the front of the hood and tighten the bolts
In the interest of perfect sheetmetal, the access panels can also be coerced into perfect alignment with hand pressure or judicious use of a screwdriver pry bar. The 8mm bolts can be loosened to raise or lower the panel... Also, the panel covering the wiper motor can be adjusted and shimmed up by placing washers between the mating surfaces.
If you are getting ready to paint, get all this done prior to going into the paint booth! Panel alignment is not difficult, if you can think on 3 planes. It is finicky work, made difficult by thin sheetmetal and a weak unibody mounted to a racy suspension. Things move around...If you have problems, try sticking paint sticks into the gap you are trying to adjust. This will help get a consistent gap.
If your hood does not fit between the fenders, your unibody has allowed the strut towers to move inwards. A tool called a "Porta-Power" will hydraulically stretch it. Great tool, about $100 from Harbor Freight. BTW, any Z hood fits any Z up to and including the 280Z.
Can we talk about Bondo for a minute? Body work is a mystery to some. First the ground rules to dispel some myths: Modern fillers are ultra light and the adhesive is very aggressive. They are also somewhat flexible. They stick best over very coarse scratches from 36 grit sandpaper. You can safely apply thick amounts of filler with no fear of cracking. The correct tools for this job are sanding blocks. I have a 18" board sander (long board) and several shorter ones. Any discussion of panel alignment usually brings up the subject of filler. The Z front end has some very thin sheetmetal, that can benefit from filler for rigidity. The idea is to put too much on, then sand it off with the longest board sander that you can use on that area.
Applying too little filler to an area will just create more work. I can't tell you the number of times as a kid that I used a dab here and a dab there. I ended up applying filler over filler in order to smooth the transition line into the sheetmetal. Very time consuming! The best way (not the easiest) is to mix up a large batch of filler and apply it to the entire area, including several inches past the area. The long board will flatten it all out. Really all a long board does is to average out the surface altitude. But to the eye- it's perfectly flat.
For example, the headlight pods always seem to be out of whack. After trying to adjust with the 8mm nuts that hold it to the fender, it may be time for filler. Rough up the metal (or 'glass if your pods are fiberglass) and pour the filler right onto both surfaces, filling the seam. Smooth it into the basic shape before it hardens. Now take a long board (a 10" in this case) fitted with 80 grit and make the fender and the pod perfect. This technique will allow perfect panel alignment! Recut your body seam with a razor blade. using a straight edge or tape as a guide to get started. After you get the blade down to the fender, you can fold some 80 grit in half and run it through the cut for a perfect body seam. Same same for the door/fender seam or the hood/access door area. Pour it on, sand it perfect, then reestablish the seam.
Professionals do it this way, whether they admit it or not. Filler won't stick to masking tape, so use it where you don't want filler (i.e.: the water groove under the hood access door; or the inner face of the door jamb).
Finally, buy quality filler from a professional paint store. Paint stores will be happy to teach you how to use their products. They make more money that way. I had a technician actually take me out back with my fresh black enamel job and teach me to color sand and buff! There are new products and technologies coming out all the time, and unless you work at a body shop and are invited to vendor tech sessions- you won't know about them. ASK the paint store guys! I used to think water borne primers were goofy, until I tried to wet sand a cured coating. Yikes, it was hard as a rock, and impervious to water. Great stuff, the gun cleans up in the dishwasher, and it is friendly to the environment. Pro paint stores will lend out paint guns as demos. I borrowed a gravity feed gun and ended up using 1/2 the normal material ( $120 worth). 2 paint jobs with the new technology and I saved enough to buy that gun!
Don't forget to primer your filler with a catalyzed primer (I like PPG K200). Check your sanding by blowing on a very light transparent coat of black- then sand it off. Use 400 grit for this step. Low spots will still be black. This is called a guidecoat.
If this was informative and useful, please e-mail me more questions. If not, I'll shut up.
Good luck. Scott