Which Speedo gear.

-
65PlumCrzy

65PlumCrzy

Well-Known Member
Joined
Nov 7, 2014
Messages
200
Reaction score
16
Location
Gaston, SC
I've been looking at gearing charts all night and have narrowed my options down to two speedo gears, a 41 tooth and a 43 tooth. Every chart I've looked at has a different option to use. I'm using a BB 727, 4.11:1 gear, 245/40r18 ET streets, and not sure what gear I need. From what I've read the 245 calculates to a 25.7 Diameter tire, and haven't found a chart that has 4.11:1 gear, they show 4.10:1 with either 25" tire or 26". Has anyone figured out the math or could just tell me which gear to purchase?
 
After looking at about 6 charts, 42 looks like the right one to me. You will never get this exactly perfect, no matter what.

And you are correct, your tire is 25.7".
 
No more than 1" wide side panels for better sun exposure. Makes for a better tan line. Oh, you meant speedometer. My bad....
 
41/42 my chart has.
 

Attachments

  • speedo3gear.jpg
    29.6 KB · Views: 121
26 inch tire generally works out to teeth per gears and you'll be close.
i.e. 3.55 would be 35 teeth
4.10 would be 41 teeth
 
Thanks guys, I found a super neat equation chart late last night, and the ones that said 42 tooth are dead on. The formula came up with a 41.78 tooth, so 42 it will be. Now the task of finding one. Didn't see any on eBay, so gonna have to widen my search unless a FABO member has one they're willingly to sell.
 
Was wondering wher eyou are buying your gear from. I need to purchase a new gear and have not looked into which vendors will carry these.
Thanks Rod
 
I've been on the phone with Summit Racing, Jegs, and Mancini, the last number given to me is to a transmission company AandA Trans in Indiana. They're closed today, but plan on calling Monday. On eBay, I've found a few 42's but they say Jeep and 80-up Mopar trans, I'm searching now for differences in those parts. A and A Trans number is 317-831-3066.
 
65PlumCrzy said:
I've been on the phone with Summit Racing, Jegs, and Mancini, the last number given to me is to a transmission company AandA Trans in Indiana. They're closed today, but plan on calling Monday. On eBay, I've found a few 42's but they say Jeep and 80-up Mopar trans, I'm searching now for differences in those parts. A and A Trans number is 317-831-3066.
Click to expand...

See link above, lol.
 
Bad Sport said:
See link above, lol.
Click to expand...

You beat me to the post by a few seconds. lol. Thanks for the help and the look out. I feel better now knowing that someone else came up with the same name of a company as another. Now I have to be patient and wait for Monday to get here. :blob:
 
65PlumCrzy said:
You beat me to the post by a few seconds. lol. Thanks for the help and the look out. I feel better now knowing that someone else came up with the same name of a company as another. Now I have to be patient and wait for Monday to get here. :blob:
Click to expand...

A&A are good peeps, they are very very helpful.
 
You must log in or register to reply here.
-

Back
Top