My wife"s father gave her A 71z some years ago, I kind of inherited it when we married. Decided to give a try at restoring it somewhat. my question is, I removed the engine and all indication are that it is a 280z or zx motor. could someone tell me what I have? Its a N42 block with a N42 head. This car has not run in probably 25 to 30 years been in a garage.

While this doesn't directly answer your question, it's still a good (and short) read: 

 

This may be more helpful in answering your question: https://www.zcar.com/threads/n42-block.33669/

I think it’s a 1975 280z head on a later block, Pretty sure about the head. @SteveJ

Most likely a 1975 or 1976 280Z engine.  Originally an EFI engine.  5521 is pretty low, I'm going to guess 1975.  People often swap the carbs over and install them in their 240Z's.  Sometimes they use the 280Z tranmsission and differential also.

What type of carburetors does it have?  You'll be competing with Shawninvancouver for carb advice.  25-30 years means the gas tank and fuel system are probably rusted and gunked up.  Some work involved there.  Somewhere here on the forum or out on the internet there is a basic guide for getting an old car back on the road.  Can't remember the title of the thread.  Ways to prepare the engine to get the most life out of it after it runs again.  The cylinders tend to rust even sitting inside, just due to condensation.

Check out the Resources area - https://www.classiczcars.com/files/

 

11 minutes ago, Zed Head said:

Somewhere here on the forum or out on the internet there is a basic guide for getting an old car back on the road.  Can't remember the title of the thread.

"Wake The Sleeping Beast" or something like that.

@siteunseen will be along in a moment to point you to the correct thread.

Wake up Cliff! Where are you friend?

If our decoding method works, the engine block was casted on 9th of January 1975.

“5109I”  5=1975, 1=January, 09=9th, 

I=alphabet /ai/.

Does it make sense to the number L28-005521? 
 

Kats

 

Edited May 10, 2024May 10 by kats

7 hours ago, Captain Obvious said:

"Wake The Sleeping Beast" or something like that.

@siteunseen will be along in a moment to point you to the correct thread.

You mean like this?

 

4 hours ago, SteveJ said:

You mean like this?

Oh great. Now what's Cliff gonna do????

Consume more Beer!! 🍻

Thx everyone the info was much appreciated. Car was in pretty good condition(compared to some I seen that guys went ahead and restored!) usual rust battery holder, and floor pans, rest of the car was solid(so far). Emptied the fuel tank(must have been full lol) and inside looks to be just varnish. Fan belt was rotted out and broke but I turn the crank over by hand and spun easily. Carbs appear to be round top SU's.

 Not looking to do any serious modifications but would like a little more pwr. (as "Tim the Toolman" would say OH OH OH!) Maybe some flatop pistons, change out points distributer and a header. I'll have to check the forum for some answers on that. thx again.