Is it a 3 or 4 speed? If it's a 4-speed floor-shifted unit, it's probably a SM-420, the original-equipment transmission. The 3-speed column shift with the torque tube would also be original. Either one will have the same transmission bolt pattern as the later-model open driveline trans.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!