New guy 79 factory 4 speed wagon.

[t5montecarlo]

I have an app that I made in Excel many moons ago.

You want a driven/drive ratio of 3.0175 with that tire/rear combination.

Speedo Gear Options (I don't know how many of the driven gears are possible; the best option is probably 7/21 (1:3). The MCSS uses with 1:3 gearing with 3.73 rear gears and the Camaro/Firebird use 7/21 in the T5 with 3.73 gears)

drive	7​	8​	9​	10​	11​
driven	21.12​	24.14​	27.16​	30.17​	33.19​

Each combination will be off by -0.58% or -.35 mph at 60 mph.

 

[t5montecarlo]

There are also websites with calculators that will calculate the gearing you need.

 

[Mighty]

Tried 2 online calculators. 8 tooth drive gear in the super t10, 3.89 rear ratio, 26 inch tire. Both times I came up with 24.12. So I assume if I buy a 24 tooth gear for a muncie/turbo 350 it’ll work? I’ll keep looking for a super t10 specific one

 

[t5montecarlo]

If you already have an 8-tooth gear in the Super T10 now, the bad news is that I don't think GM had a driven gear greater than 22 teeth. You could use the 8-tooth drive gear and a 22-tooth driven gear and find a place to order an adapter to attach to the driven gear sleeve with a ratio of 0.9114, or use a 21-tooth driven gear and get an adapter with a ratio of 0.8699. GM used adapters on some cars when the drive/driven gears didn't work out. It would be easier to use the 7/21 combination.

 

[Mighty]

This is what I was looking at earlier?? Also my brother said if he remembers right the monte parts car is a 85. He’s had it for probably 15 years or better and I just recently picked the screws off of it for the fender wells in my wagon. If there’s anything you need I’d be more than happy to look around for you after all the help you’ve been.

 

[Mighty]

Just came across this. Sounds like the 8 tooth is only compatible with a 6 driven gears….

 

[t5montecarlo]

From the interior, is the small screw that holds the trip odometer knob still there? I am missing that tiny female screw.

You may want to contact The Gear Box and/or SS396 directly. The drive gear listing states it is only compatible with 17-22-teeth driven gears (which agrees with the GM parts books), but ss396.com advertise a 24-tooth driven gear to fit. Is it a custom-design gear because GM never made it? What driven gears is it compatible with?

Or get a 7/21 combination and no worries.

 

[Mighty]

I’ll run out and take a look today

 

[Mighty]

Is that tiny little flat blade screw the one you’re referring to?

 

[t5montecarlo]

Yes, that's the one!

Was that car under water? It looks like a waterline on the gauge lens.