Speedo gears question

[k3522]

I am not sure what gear is in my tranny but accoring to www.mymopar.com/speedometer.htm I need a green 31 tooth part #2838931.

My question is I have a new small diameter black 34 tooth and a new larger diameter green 33 tooth that were given to me by the prior owner of my Dart. I was going to try one of them to see if it would give a more accurate speed reading but then I thought is the larger diameter gear for a 727 tranny and the smaller diameter gear for a 904 tranny?

Any help would be apprieciated.

 

[RedFish]

The speedo gear housings are ecentric to accomodate different diameter / tooth count gears.

 

[rumblefish360]

No, the diameter is for speedometer correction. Both tranny's use the same gear. Later year trannys switched to a different type of gear. Shorter and clip on.
If you need a 31 and have a 33, use it. It'll be closer than a 34, but not much. You can order these gears from your Chrysler dealer or Manciniracing.com

 

[redfastback]

If you go to moparts they have an excel program that will get you as close as possible to the correct tooth count.

I got my gear from brewers performance.