fbekholden.com

Hi all
Doe's anyone know a formula to work out what gearbox gear (gear in gearbox ) to speedo to use for a 305 chev /turbp 350 i think the roll measurement may be needed but at this point in time that is unknown till tomorrow hope you know what i mean.
Billy

Best way I've found is road test Billy. Not much help if you don't have a gear to start with. They usually have around 20 teeth. Each tooth you add slows the Speedo by around 5%.

FB ute driver, EK van project

Few calculators on line that may help

Regards

Gazza

You'll need to know what colour drive gear is already inside the box. You can then pick a driven gear to suit (can change both if needs be).

viewtopic.php?f=27&t=18598&p=189353&hil ... ur#p189353

Cheers,
Harv

Billy , TCI transmissions website has a real good calculator, also tells you what colour the gears are so you can see the colour of your drive gear inside the box and try and match a driven gear to it - all you need to know is your diff gear ratio and rear tyre size , if you don’t know tyre height there is a calculator to work that out online too just Google tyre size calculator and put your size in and it will give you the height

http://www.tciauto.com/tc/transmission- ... gears.html
Blacky I found the website you suggested but cant find the calculator
Harv read your earlier post ( a bit technical for me never was any good at math )
Where can i buy the gears locally any ideas

TCI calculator:
https://www.tciauto.com/speedometer-gear-calculator

Speedo gears are available from Rocket.
https://shop.rocketindustries.com.au/products/TCI880007

Cheers,
Harv

here it is mate -

https://tiresize.com/calculator/