Speedo Gear

I'm restoring my 1940 Ford Deluxe and have gone from a 3.78:1 rear end to a 3.25:1. The 3.78 uses a 19tooth Driven Gear. The 3.25 uses a 17tooth. The Drive Gear stays the same.
I've just discovered that in order to change the Driven Gears, one has to change the Gear WITH the little Housing.
See attached photo of my 19 Tooth Gear.
What I need is the same but with "17".

Can anybody help me out ?

Thanks
Greg

 

This is posted in the wrong section but if you see this check with Rusty he is the go to guy .

https://www.speedoservice.com/

 

What you want is what is referred to as the Turtle, and yes they are used as a set.

 

My buddies 40 ford we ordered a speedo correction

 

There is a guy on fordbarn that goes by "barnfind08" that claims he has some NOS 17 tooth gear, and caps.