Timing gears in 990 and 1200 the same?

[dieselherb]

I have a 1200 in need of timing gears, I was told the 990 and 1200 are the same engine. My 990 has a AD4-74A engine

 

[RGMartin]

The 1200(4-55 engine) is the same as the late 990 with the 4-49 engine.

The early 990 with a 4-47 is a totally different animal.

 

[dieselherb]

(quoted from post at 17:34:02 09/01/23) I have a 1200 in need of timing gears, I was told the 990 and 1200 are the same engine. My 990 has a AD4-47A engine

 

[dieselherb]

Looks like I have the different animal