Having done several of these, it's a good idea to buy a new input shaft. I swapped input shafts from my old 249 into a new 231, and because my input shaft had some wear on it, it caused it to mesh a little off..which caused pressure on the shift forks...which melted the plastic pads on the shift forks....which caused the shift fork to explode...which caused it to be locked in 4 lo...which caused me to drive home 70 miles on the freeway in low range.
Also, I can't remember which years, but certain years of 231's have steel shift forks and some years have aluminum. The steel is preferable for durability. In 93, there isn't any rhyme or reason for input shaft length and you could have 1 of 3 different lengths. Once you pull out your case, you will know and you can either go to a place like Tourist Transmission and buy a new one, or swap your old one over. Like I said, my experience swapping parts didn't work out so well, but others have done it without incident.
Cody