As far as my records show, the '89 GT-R (as you call it - the specification didn't change from 08/89 to 02/93 actually), and the '93-'94 GT-R (not V-Spec/V-Spec II) only differ in that the '93-'94's had an air-bag as an option, along with the White and Greyish Blue Metallic colour option for the '93, and '94, except the '94 dropped the Greyish Blue.
Now, your just talking about the plain-old;) GT-R aren't you? Not the V-Specs right?
As for the GTS-T Type M:
The 05/89 - 07/91's offered just the basic colour line up from the Skyline range, your reds, your blues, your silvers, your blacks (most popular) your dark greens, and your whites. It weighed 1260kg MT, 1280kg AT. Sunroof's were an option, as was air-con, so it's a mixed bag on what you'll get. Now, the big one: THE '89 - '91 Type M CAME WITH FRONT AND REAR STABILIZERS AS STANDARD.
The 08/91 - 10/92, and the 11/92 - 07/93 Type M don't differ too greatly except for some stupid colour differences that I cant be bothered pointing out, but the main things are: these cars are heavier than the '89, 1320kg MT and 1340kg AT, and that these cars didn't have front and rear stabilizers as standard.
So, to answer your question, No, there aren't any big differences between the model years, except for the '89 - '91 Type M with the stabilizers (thats why I got an '89 over a '90). But, obviously the GT-R's and the V-Specs are different, as is the GTS-T to the Type M.