Technical Using a Speedometer as a Tachometer?

That is exactly what I wanted to know: thanks!

 

https://www.ebay.com/itm/1671829545...eIHCculQee&var=&widget_ver=artemi***edia=COPY
An acquaintance of mine on eBay is liquidating his grandfather’s speedometer parts and equipment from his speedometer repair shop.
Bryan has a demagnetizer listed if you’re interested. I purchased many parts and some equipment from him.

 

and @Ned Ludd
Just a follow up to my post # 55
I was up in my ceiling looking for "treasures" and I found this.

This is how I converted a "Smiths" V6 6000 rpm tach to a 4cyl 9000 rpm [keeping it OEM in the dash]
When I printed the face I got a spare made .
On the original Smiths Tach the indexing was printed on to a faux gl*** face, so I removed this.

If anybody in wanting this "for a good cause" just message me.
calling @Mikko_ [is this something that would suit your Cortina project?] You'll need to find a V6 tach from a Mk4 Zodiac which is a direct fit to the Cortina Dash

 

@Kerrynzl I appreciate the thought but I think the shipping from NZ would be quite high, and hard to find a Zodiac tach around here.

But thanks that you thought of me.

 

I've been looking at an OT DOHC V8 which offers relatively easy access to the back of the intake cams. Moreover, the intake cams turn anticlockwise when viewed from the rear, so a pair of small spur gears with 16/30 teeth in a fabricated housing would give clockwise output at the proper speed from the driver's side intake cam. The p***enger-side intake cam would offer a site for a distributor — or magneto if I'm feeling up to that can of worms.