There was a tme when I could shift a two stick rig like I knew what I was doing, but its been about 30 years since I've had occasion to even try.
I remember like it was yesterday the time the transmission in that truck basically exploded. Empty truck shifting only the primary and using the clutch. I believe someone else must have done something bad and I was the lucky one behind the wheel when it let loose.
About 1980 it cost $1,000 for either the parts or a replacement transmission. I did get to install the new transmission in it.