Swapping out factory 5 speed for 6 speed...

[1BAD10]

I'd like to swap out my factory 5 speed for a 6 speed. From what I understand, the 5 speeds are inherently week. Any pro's/con's? What all is involved?

 

[Justin S]

The NV3500s can handle quite a bit. Unless you're looking to swap in a big block or boost your small block, it should be fine. The biggest con would be the cost of the swap. Most likely just need a different driveshaft.

 

[Chewy1576]

Depends on what 5 speed you're talking about. The NV4500 is plenty strong for a 5 speed manual gearbox. It was behind all GM big block and diesel engines, and Dodge put it behind the Cummins. If you had a parts truck with a usable NV4500, you would have all of the parts needed to make the swap.

GM didn't offer a 6 speed manual in an HD application until 2001, the ZF S6-650. From what I understand, it has a big case, and will need a body lift to get it to fit. That is, if it will bolt to whatever engine you have to begin with.