anyone know how to tell if 4 speed is overdrive

One easy way is simply figure out the ratio If the levers are correct, the front shift lever should be pointing DOWN instead of up. That is not always definitive. With the gearbox in neutral, move the front shifter CW, which puts the gearbox into 3rd gear (overdrive if it's an OD box) Rotate the input shaft one revolution, and see if the output turns more or less than one turn. LESS than one turn is a standard 4 speed, MORE than one turn is an OD box.