I don't know for sure on the diesel trans, but the 2WD 5Spd I have out of a gas 2.3L 88 Isuzu Impulse is the same length as the stock 2WD LUV 4Spd. The 4x4 5Spds are longer. I don't have either here to measure, but once someone can comment on the stock length that will give you something to work with.
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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)
MEPR: Man, my 4x4 makes all other LUVs look good
