Can anyone help me identy what year and model of truck this transmission came from?

It is a 4 speed with the shifter entering at the top. Is has no cross member mounting bracket. Does not really have a tail case and uses a U-joint yoke on the output shaft. Gear shift pattern is the stardard "H" with reverse toward the driver and back to the rear.

Top cover has the numbers GM 3, 591588.

Numbers on the side of the case are:
B2381, 14 GM T, 3787239

It is short but looks pretty heavy duty.

Thanks