[Hodo]

Well Gigi, first I would like to say sorry about the asses you had to deal with before. And you are right the Fairlady is VERY picky about the kinds of people who work on them. And BTW where do you live I dont want to have to deal with those companies you have delt with before.

Now heres my little assessment of the whole situation.
Its not bad. Sounds like it all started when the first guy did the work on the car, he could have creased or crimped a gasket as he was putting it on, very common on straight sixes, and or the head or deck is warped. This would cause the reacuring problems you keep having with the gasket and the water leak. As for the EGR and the oil pump that happens over time if something is wrong elswere. So far you have been pretty lucky, but I will say it will probly get a bit pricy now to see what is exactly wrong. You can do most of this yourself you seem competent enough to check your own head and deck for warpage.

Step 1- go to Sears, Snap-On, Matco tools, Ace Hardware, or anyplace like that that sale good straight edge tools. You will need a meter long perfect straight edge. The dont cost to much and some machine shops can make you one for pretty cheap. Also you will need a accurate set of feeler gauges, get some good ones these will help with the checking.

Step 2- remove the Head and gasket from the engine, make sure to remove all the oil and coolant from it too, and just to be sure the battery, you dont want to accidently bump it over while you are in it. Hand turn it till it is just past TDC (top dead center) for cylinder 1. Then take your straight edge and lay it across the engine deck diagnaly(doesnt matter which way you start front left to back right or front right to back left.) take your feeler gauges and try to slide the smallest thickness feeler under it, without moving the straight edge, do this on the raised parts of the engine the parts that are in contact with the straight edge, not down in the cylinder holes. (( I have to say that becuase I have seen some dumb asses place the gauges down in the cylinders between the piston and the straight edge.)) Make sure to check on each area that makes contact with the edge. Write down the size of the feeler that slides through and the place on the engine. This will help in determining if its warped.

Step 3- After you have measured across the engine deck diagnally go straight back, from front to back and do the measurements again. Write them down like the others. The total measurements patern should look like a X with a I going through the middle.

I hope you are following me so far. Cause its hard to explain without being able to draw it out.

Step 4- turn the head over so its bottom is facing up on a table or work bench. Do the same measurements again with the straight edge on the head. Same X with I, write down the numbers again.

Step 5- find the specs for what the head and deck should be within. But trust me if its warped you will have a wild set of numbers completely different than the others on either the head and or the deck.

If the head or Deck is warped thats not bad news either, just find a good reputable machine shop to see if they can work them back into specs. This may change the compression ratio a hair but nothing a thicker gasket cant fix. And then everything should be a good as new, and you didnt have to get a new engine.

Hopefully Albert comes on and helps out with this post I just turn wrenches for Volvo and Lincoln/Mercury/Ford, I havent had to do a head/deck check in a few years.