speedometer cable

[Buckaroo]

Our project car we just bought, 1957 Fairlane 2 door hardtop, did not have a speedometer cable installed.  I have ordered a manual but it is back ordered.  Could someone tell me where to route the cable through the firewall.  This car has a 390 engine installed so the routing may be slightly different.  The back of the engine seems pretty close to the firewall.

[Ford Blue blood]

If I remember correctly there is a hole to the left and just above the removable plate that is around the steering column.  Been a couple of years since I put one in but I recall the hole being very tight with respect to the ring that fastens to the speedometer back.

[Buckaroo]

Thank you.  I will check it out tomorrow when I get back into my shop.

[Buckaroo]

Thanks for the info.  I found the hole.  It was covered by a rubber pad from the newer steering column being installed  I installed the cable today.  This spring we will see if the speedometer gear is correct.  I used the one from the Tbird tranny.  I hope it is close.  Thanks for the help.

[lalessi1]

I have a lot of info on speedometer gears. I can help you get the right one when you get to that point.

[thomasso]

Lynn:  I have a T85 OD and a 4:11 rear gear in my Sunliner.  Can't seem to come up with a proper driven  gear.  Its the larger dia. gear.  Am using a 20T gear and its way fast like 15 MPH at 60.  have been unable to access a larger number tooth gear to fit.  A 4;11 isn't listed as a 57 ratio.  Any suggestions?  Thanks.

[Buckaroo]

The Birds Nest, a Thunderbird parts house, lists a 21 tooth gear.  That may get you a little closer.  Otherwise, you can get a GPS speedometer.  I am not certain how well they work but have seen them advertised.

[thomasso]

Thanks;  I think I need a 22 tooth gear.  My wifes smart phone has that feature and it is very accurate. Alas I'm only smart enough to use a flip phone.  If only someone made an external in cable adjustable speed reducer.  I'm only aware of fixed ratio ones as used on some trucks.

[RICH MUISE]

JFYI...........I love my GPS speedometer. My regular GPS and the Gps speedometer are always indicating the same mph, so I'd have to think they're pretty accurate. With the GPS speedometer you'll never have issues with changing gears or tire sizes.............has zero affect on the speedometer. I got mine from Speedhut. Downside obviously is it won't fit in the oem dash panel, but if you're thinking a custom dash insert, GPS is the way to go. I've got about 32k miles on mine now with no problems.
Pic below is when I was changing over from TPI to Speedhut. In this pic, only the speedometer is Speedhut

[SkylinerRon]

You can get a speedo gear box to correct for most any gear/tire combo. Ford used them on 4.30 geared DragPak cars. Speedometer repair shops have them.

Bill's Speedo in Michigan if none local to you.

Ron.