Unless you get a donor truck that is a manual trans, you can switch to a NV4500 or TREMAC 5 speed, they are the most popular.
I do believe your 87 is a hydraulic clutch so it has to around an 87 or so, not sure how far back into the earlier 80 had hydraulic clutches.
Someone will chime in and tell you what years of square bodies are a simple switch over, the other transmissions will require more work.