Differences in block years 83-86 86-88

Allright, what are the differences in the turbo coupe blocks between these years and how do I tell what I have? I pulled the engine from a junk yard and didn't pay attention to the specific year the vehicle was and now I'm about to put the thing back together and need to make sure I have the right year rings and bearrings. I just spent over an hour trying to search for this info to no avail. Very irritating, but please, please tell me how I can determine what year my engine is. I can't seem to read the block casting numbers, seems to have been rubbed off or something...Also the engine had the turbo taken off so I don't know if it's an IHI or a T3. I have a T3 to go on it, but not sure what it originally came with.
 
Allright, went out and bought a chiltons for the t-birds, the only thing that's not 100% the same from the 85 year and say 87 is...

main journal size

85 2.3990-
2.3982

87 2.3982-
2.3990

Being how the numbers are the same just in a different order I don't think that makes a difference. Which leads me to believe that between these years the only difference isn't internally, but possibly gasket related...hmm...

Please, someone help guide me.

Oh, wait, is it the intake ports that are different? I recall something about D-shaped ports on a certain year... I might be getting closer, but some confirmation on the interals is greatly appreciated...and an answer to my original question.
 
Thanks for clearing that up for me. One more thing though, I don't recall when I tore into the engine whether the rear main seal was a one piece or a two piece and I can't find anything that would work in my felpro gasket kit. I'm just wondering if it wasn't included for some reason. I'll probably just go buy one tomorrow, but that's annoying that the rear main seal isn't included.