RPO code MY6 in a 1990?

[curbstone mech]

Why would a 1990 Silverado 4x4 have an RPO code of an MY6 transmission? I'm hoping that it is an A833 trans but could it be an NV3500? I thought that the A833's weren't available after 1987.This truck has the 4.3 engine in front of the trans! I want to grab the trans for my square body 79, but something seems strange.The rpo codes are still there in the truck and even the owner's manual stating that its a 1990. I'll have to lift the truck up out of the weeds before I can do a visual.

 

[RetroC10Sport]

It's an SM465.

 

[Keith Seymore]

No - MY6 was gone by 1990.

https://www.gmheritagecenter.com/do...its/Chevrolet-Trucks/1990-Chevrolet-Truck.pdf

K

 

[RetroC10Sport]

No - MY6 was gone by 1990.

https://www.gmheritagecenter.com/do...its/Chevrolet-Trucks/1990-Chevrolet-Truck.pdf

K

MY6 was the RPO for provisions for a 4 speed manual. Used until 1991. MM4 was the RPO for the 4 speed manual - SM465.

 

[curbstone mech]

Thanks for the replies. I guess I'll start looking for an NV4500 again

 

[Keith Seymore]

MY6 was the RPO for provisions for a 4 speed manual. Used until 1991. MM4 was the RPO for the 4 speed manual - SM465.

Let me say this differently: the New Process A833 was gone by 1990.

Technically MY6 and MM4 are "merchandised" option codes, related to the "non - merchandised" codes of MY0 and M20, but I can see where it could be said they drive the "provisions" for their respective content.

K