How to indentify model numbers on outdrives ?

[redbreast]

Cant find identification number on my outdrives any body know where they are sighted, please. Volvo Penta Duo props 1991

 

[DoubleVision]

Should be on the plate on the upper gear housing just below the steering yolk and where the gear cable enters the leg

 

[redbreast]

Hi thanks for quick reply Im not an engineer, so would that be inside where the outdrive is or on the exterior part of the leg itself.

 

[Col]

Likely to be 290A.
If it has a prop cone bolt that you undo with a 13mm socket, its a 290 a, If 17mm it will be 290B