A833 trans gear question

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Michael Nelson

Michael Nelson

1974 Dart Sport 360 4 speed
Joined
May 12, 2021
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Location
Trevor WI
I have a a833 non OD trans and I just took it out of my car to inspect it over and clean all the cake off of it. Some of the gears have three slits on all the teeth all the way around in the exact same positions.
No metal and no bits.
They definitely look machined, but other pictures I've seen don't have it...
Is it just to hold lube?

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Michael Nelson said:
Thank you I have them a call and they told me it's a 71 A-body 2.47 close ratio!
Click to expand...
Before you get overly excited, that trans (yes I have one) may not be what you think it is; It's not like a Muncie close ratio.
In my experience a good second gear for a stout 360 is around 6.82. This will get you about 11.77 mph per 1000 rpm so; 3500 is 41 mph, and 60 is 5100. This allows a nice 268* cam.
Below are the Mopar boxes, with splits first column to the right.
In the Third column, are listed the rear gears required to get this 6.82
In the Fourth column is your cruise rpm with the nearest diff @65 mph.
In the Fifth column are the starter gears


2.47-1.77-1.34-1.00 --- .73-.76-.75 --- 3.85 --- 3165 (3.91s) --- 9.66
2.66-1.92-1.40-1.00 --- .72-.73-.71 --- 3.55 --- 2873 (3.55s) --- 9.44
3.09-1.91-1.39-1.00 --- .62-.72-.72 --- 3.57 --- 2873 (3.55s) ---10.97
3.09-1.67-1.00-.73od --.54-.60-.73 --- 4.08 --- 2428 (4.11s) --- 12.70
same od box but3.91s gets you a 6.52second--2310 (3.91s) --- 1208

Happy HotRodding
 
Last edited:
AJ/FormS said:
Before you get overly excited, that trans (yes I have one) may not be what you think it is; It's not like Muncie close ratio.
In the Mopar Close Ratio, the desirable part happens on the 3-4 shift, which with the 3.91s (what it will take to get that Dart Sport moving), top of third gear is ; 5500=84 mph. So I mean, how often are you gonna be up there? and
Still with 3.91s; 5500 in First is about 46 mph, on the 1-2 shift the rpm will fall to .76 x 5500=4200 which is a great Second gear but is it worth running 3.91s and 65mph=3200?
The 3.09 trans will give you the same 10ish to 1 starter gear, but 65=2615, and 46 mph in Second gear is 3535, so yur engine-build is gonna be a lil different for absolute performance, as in forget about a 292 cam.

Here are the Mopar ratios; first yours, then the standard, then the Commando. and beside them are the splits. Third column is the rear gear required to get a decent starter gear of just over-around 10 to 1.
2.47-1.77-1.34-1.00 = = .73-.76-.75 = = 3.91/4.11
2.66-1.92-1.40-1.00 = = .72-.73-.71 = = 3.73
3.09-1.91-1.39-1.00 = = .62-.72-.72 = = 3.23

Happy HotRodding
Click to expand...
Thank you for the information, my budget is limited with me going to school and stuff, I was happy to know its a decent trans, plus someone rebuilt it at one point, so I'll run it till it dies.I know very little about some of this stuff, one of my customers gave me an 8.75 with 3.91 sure grip which is what I'll be running once the car is drivable again. It had 3.23 and it moved but felt kinda slow so hopefully the new rear gear wakes it up a bit.
 
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