Gearbox identification
 

I have the opportunity to buy some sportomatic gearboxes (to replace or repair my broken one) I 'm only 90% sure about which ones are four speeds and which are three. Before I but them I need to know what they are. I have some identifying no.s but my spec book isn't comprehensive enough to allow me to identify them. Can anyone identify these?
Type 925/09 7662081 (suspect 3 speed as 09/12/13 are all 3 speed to my knowledge)
Type 925/15 7676121 (seems to be a 4 speed according to the movement of the input shaft, but the 'Park' ‚ position is confusing and the serial doesn't make chronological sense)
Type 925/16 7671157 (think this is a three speeder)
Type 901 (type905/21) 7430054 (this seems to be an early 70's 4 speed)

My reference says all 925/09, 925/15 (1977 model year with serial # 767####), 925/16 are three speeds.

Also says that the 905/21 is a four speed for 72 and 73 (with serial #'s starting with 742#### and 743####). Refers to the car model as 911 TV but I don't know what the V means.

Hope that helps some. Not too familiar with Sportos..........

Thanks that helps a lot what's your reference by the way?

Porsche parts software. From the Transmission Code page(s)

Ah haven't got that (yet)