Confirmed, L series 4 speed made before '80, has top gear and neutral gear switches so not from 810 or 280z or first year '79 290zx. This leaves only the 620 truck. The '79 used a 4.11 differential so a wide ratio transmission was fitted rather than the mid ratio to make starts with heavy load a little easier. First and second are a little lower geared but third and fourth are the same as the mid ratio four or five speed for that year. 

Mark the input and output splines, place in first gear, turn input spline 20 times while someone counts output turns.

5.5.......... wide ratio

6.0.......... mid ratio 

Danz 1

Posted July 13