No they aren't... I have had a few different sets... they are different between years, trim, model, etc.
Your BEST bet is to get one from a similar NA or T that has near the same production date as yours. They do have a "partnumber" tag on 'em, but I've seldom seen these match up to each other. My Canadian model was different that the same year US, etc.
I have a few extra and some are already tore up (cut spliced, etc), but if you give me your partnumber off of yours, I'll take a look.
The best thing to do, if you realy need to, is to get the front body harness and dash harnesses from the same parts car to replace yours. There are subtle differences adn you won't find them out, 'til after you've gone thru all the trouble of installing and finding that 1 connection is different, etc.
By the way, one big difference is in the passenger fender where the dash and front harness meet. The 89+ are square plugs, and the earlier ones are round. However, in 89 there was a mix of the 2 and you never know which you'll end up with, so I'd at least verify that, before buying it from someone else.