1964 Riviera ST400 Speedometer driven gear

[RiVin]

I do not have posi.  I tested that long ago.  Also, the 3.07 supposedly was never offered with posi......so I'm told.  Lastly, the bottom of my pumpkin is stamped 3.07.  And thank you for the calibration info.  

[telriv]

My '64 which I ordered new had a 3.07 rear & I ordered posi which it still has today.

 

Tom T.

[Turbinator]

Awhile back I put a white color plastic gear driven widget in the transmission of my 63 Riviera in hope of getting accurate speed indicator on my speedo. The speed readout was close, but I wanted a tiny bit more accuracy on the speedometer. Tom Telesco told me about an instrument company in Texas that could help get an accurate read on speed. The company asked me to measure beginning and ending reading of the odometer over a measured mile. I did the drill a number of times at different places along Interstate 83. I sent the readings in along with a $150.00 check.

After two or 3 eeeks I got my speed compensator instrument. Surprisingly, the instrument was easy to install.

im satisfied with accuracy being right in until I reach 70 mph plus. The speed reading begins to differ as much as 3 mph when compared with a GPS app.

Could be the GPS is a tad bit in error?

I could use two different GPS apps on two different smart phones and report my finding regarding speed readout.

I have two different sets of 4 tired and wheels. One set are 4 modern radials and the second set of 4 tires are radial bias look. The speed seems to have the same level of accuracy for each set of 4 radial tires.

Turbinator

[RivNut]

It’s been my experience that the base ratio for first generation Rivieras was the 3.07.  3.23, 3.42, 3.54.and 3.91 ratios were optional except for the 1965 Gran Sport which had the 3.42 posi.

[RiVin]

13 hours ago, RivNut said:

It’s been my experience that the base ratio for first generation Rivieras was the 3.07.  3.23, 3.42, 3.54.and 3.91 ratios were optional except for the 1965 Gran Sport which had the 3.42 posi.

We all might benefit from this chart that I found on the ROA website.  https://rivowners.org/features/Ev_Stats/axleratio.html#:~:text=1964 - Location same as 63,)%3A 3.07%3B 3.23%3B 3.42

This should help with axle identification and availability by years.  Best regards

 

[1965rivgs]

1 hour ago, RiVin said:

We all might benefit from this chart that I found on the ROA website.  https://rivowners.org/features/Ev_Stats/axleratio.html#:~:text=1964 - Location same as 63,)%3A 3.07%3B 3.23%3B 3.42

This should help with axle identification and availability by years.  Best regards

 

  The description of '65 axle identification in the chart is incorrect. The description of '63-'64 markings carries over into '65.

Tom Mooney

[RiVin]

1 hour ago, 1965rivgs said:

  The description of '65 axle identification in the chart is incorrect. The description of '63-'64 markings carries over into '65.

Tom Mooney

Man, this is crazy. I guess that the only thing you can trust for information is things on your car that you can see and touch.  So confusing.  But I still love my 64 Rivi.

[RivNut]

A lot of things on the ROA website are put together by guys like you and me based on the best info we have. But it’s never verified before it’s published. Keep that in mind anytime you look at it for advice