I remember those. I drove a five speed van with one. What were those called anyway, chevies little van.
As christ said the engine, it is a heat keeper. the trannies absolutely hate it. Even the forward yoke could melt.
the four speed is a bit more brut internally...and the fuel, because of the heat soak, it is a perfect candidate for hypermile.
clean that engine as much as the truck. if egr'd do away with it.