620 tachometer substitution?

[EDM620]

I'd like to find a tachometer to stuff into the hole on my dash. Has anyone found something that fits?

[datzenmike]

The 1200 or B-110 used the exact same optional tach but it had a flat plastic face. I had one and cut up a gauge cluster for the plastic cover and glued it on to match the other two.

 

There is plenty of room for just about any after market tach you care to try in the hole. The '75 didn't have any wiring for a tach so you will need to run a sense wire to the coil negative side.

 

Amazon has 7 pages of tachs. Digital are impossible to read when the numbers are changing rapidly and a needle is much easier for a quick glance. Red line for the L20B is 7K so you don't need one that goes to 10. I'm not suggesting you get this one but it's clocked to place the average usable high RPM reading in the 11 to 2 o'clock range

 

https://www.amazon.ca/Riloer-Tachometer-Colors-Tacometro-Universal/dp/B09MRXZHDX

 

 

Rather than 12 to 4 o'clock.

 

[EDM620]

2 hours ago, datzenmike said:

Digital are impossible to read when the numbers are changing rapidly

Very true Mike, I'm not a fan of most digital instrumentation - tachs or speedo's especially. No subsitiute for the ability to make a quick glance rather than actually having to read the #. Funny how luxury cars still use an analogue clock and some without any #'s - can millenials tell time that way?

 

2 hours ago, datzenmike said:

it's clocked to place the average usable high RPM reading in the 11 to 2 o'clock range

Part & parcel of the above. 

 

I will pull the 620 dash out of storage soon and see what mods I'll need to do and what diameter gauge to order. I'll be running the 720 electrics which does feature tach output, and be adapting the wiring to the simpler 620 instrument cluster.

[datzenmike]

Millennials scratch their heads when I say the distributor turns counter clockwise.

[FrankRizzo]

Speedhut 3 3/8" fits perfectly and can be customized to look like to original gauges.

Its in my build thread someplace.

[EDM620]

On 12/14/2021 at 11:17 AM, FrankRizzo said:

Its in my build thread someplace

Thanks for the tip. I've gone back through your build and found the info, and some other good stuff that I've been considering for my build as well.

[Curley]

A far as Tachometers this is what I did and I think it fits the gauges pretty good.  I purchased a this Steward Warner Tach from Summit for $129 https://www.summitracing.com/parts/sww-82170/overview/, painted the chrome ring black and slid it into place.  

 

IMG_0235 3 by briancurley, on Flickr

 

[datzenmike]

It only has to please you. Looks good.