speedometer gear???
speedometer gear???
I have a 66 mercury comet 390 3 speed stick, I am changing it to a 4 speed. I got a rug-j trans with a c70 tail, what do I do for the speedometer gears?/ Also I'm going to change it to a 3.55 posi rear, I don't have that yet but soon. Also any suggestions on the rear? Thanks
- Joe Travers
- Posts: 2452
- Joined: Mon Sep 21, 2020 6:23 pm
- Location: Louisiana
Re: speedometer gear???
Dealerships used to calculate it for you back in the day. Try this out-
https://www.tciauto.com/speedometer-gear-calculator
JT
https://www.tciauto.com/speedometer-gear-calculator
JT
Last edited by Joe Travers on Tue Dec 08, 2020 9:31 pm, edited 1 time in total.
Re: speedometer gear???
your 66 should have a 28 spline open rear.it would be nice if you had a 67 gt rear,they had 31 spline posi.
fryedaddy
1966 caliente,428 4 speed,4.11 gears,nitrous,parachute
1966 caliente,428 4 speed,4.11 gears,nitrous,parachute
Re: speedometer gear???
Check with Dan williams or David Kee toploaders. They can help you with the right setup for your rear axle ratios.