I don't know but it might.
If you'll measure length from the middle of the u-joint bearing cups and the diameter of the drive-shaft, I'll compare it to my 2wd 79 and see how they match up. If they're close we can check the u-joints and see what you'll need. The Blazer wheelbase is actually 1.5" shorter than the 78-88 G body so you might be able to cut it down and use it. Measure and let me know.