I have a 1975 280Z that I bought not too long ago. I thought I had the original engine but as I am learning more about the car, I came to find out that both the engine and tranny are not original.

I looked at the numbers stamped on the cyldinder head and engine block and this is what is stamped.

Cylinder Head: N47

Engine Block: 179109

I could not find anything on the Chilton Manual as to which year these are from. Can someone tell me which year the cylinder head and engine block are from?

I blew the head gasket. I was told that the N42 head was more desirable. Should I just buy an engine that matches my year or just rebuild this? Is the combination that I have now reliable?. I will be using this as a daily driver.

Is there anything special/unique that I should know about my engine?

I look forward to your responses.

'Desirable'. That's one of those words with many definitions. The N47 head is just the later 280Z/ZX head. For a daily driver it will be fine. The blocks are the same. That head will work fine on your car. If the car ran before you blew the head gasket, why would you want a new engine? Just surface the head (don't have more than the absolute minimun removed) and put a new gasket in.

Thanks Blake. Your suggestion about about resurfacing the head and putting in a new gasket seems more reasonable at this point.

Is there a way to identify which year my block is from with the number stamp of # L28 179109?

Are they the same for all L28s?

Kind of hard to pin down the exact year considering how Nissan didn't always keep things in exact numerical order. Based on my 78 having L28 275875 and it's the original engine I'd say yours is most likely a 75 engine or at least earlier than mine. If you look on the other side of the block just behind the drivers side motor mount you should see the block casting number. It should say N42 which would narrow it down to 75-80 and your number would tend toward the earlier side. If it has F54 stamped there, it's an 81-83, but I doubt it since your engine number is earlier than mine plus an N42 or N47 head would raise the compression on a F54 block because it has flat top pistions rather than the dished pistons in the N42 block.