Need help identifying engine year 1hdt plus additional questions. (1 Viewer)

[chelo]

I hope some of you can answer some questions I have. I have a 96 land cruiser that was originally equipped with a 1hz. The previous owner installed a 1hd-t engine and prior to installing it had it rebuilt.
The engine serial number ls 0007389 which leads me to believe is a early pre 92 block. Not sure If casting number makes a difference but it is 00621.
The reason I'm asking these questions is that I sent my injectors to get rebuilt and I have a suspicion that when the engine was rebuilt, they installed the thicker injector seats. It runs great but it has always been smokey. I'm waiting on the injectors to come back. I removed the seats and sure enough, they are the thick ones.
What are the symptoms If I install the thinner ones? On a side note, the injection pump is missing the placard so I don't have an idea of the year.

 

[OGBeno]

It’s a 1990 block.

0= 1990
06= June
21= 21st

 

[chelo]

Thank you OGBeno!!

 

[Blunozr]

I’m trying to identify the year of the 1HDT transplant in my 78 series.

My block serial number is 0041421.
I can’t seem to locate the casting number.
The crossover pipe has “Turbo” in red.

Any ideas

 

[OGBeno]

I’m trying to identify the year of the 1HDT transplant in my 78 series.

My block serial number is 0041421.
I can’t seem to locate the casting number.
The crossover pipe has “Turbo” in red.

Any ideas

Nope. You need the casting number.

It's near the back of the engine on the LH side and goes vertical.

The main bearing cap assembly has a numerical casting number horizontally by the front of the assembly near where the alternator mounts.