Assuming your pickup is a 2wd, I have a friend with a '90 or '91 who hotshots part time. He dropped in a Fuller 10spd roadranger. Said it wasn't too bad a job. Required a bellhousing adapter, air compressor, and 2" body lift, and the usual driveline mods etc.
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'93 W250, CC, 4x4, 5spd. , 4:10, Cummins w/ Mild mods, K&N, 16cm turbo, Custom straight exhaust, Lund visor w/lights, 5th wheel, Gooseneck, H. D. rear hitch-pintle and ball, Aluminum everything, Cobra 148GTL W/mods.