bb66cuda
Well-Known Member
Do all the early A bodies have the 3.09 1st gear ratio? Or is there a difference between the slants and small blocks?
Early A body 833 gear ratios
- Thread starter bb66cuda
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'64 Cuda
Well-Known Member
Don't know about all of them, but my '64 273 car came with the 3.09 first gear.
Year and Application 1st - 2nd - 3rd - 4th)
More on 833 ratios and applications http://www.slantsix.org/articles/4-speeds/applications/options.htm
1964 thru midyear 1966 A-body 3.09:1 - 1.92:1 - 1.40:1 - 1:1 = G/RG and LA engines. (These all used a 4.35" IBR.)
1964 thru 1970 B/RB engine 2.66:1 - 1.91:1 - 1.39:1 - 1:1 = (The "close ratio" V8 gearbox)
1970 T/A & AAR 340s 2.47:1 - 1.77:1 - 1.34:1 - 1:1, = 1970 thru 1974 high performance
(A 2.44 first gear was also produced in this time period and some units had 1.91:1 second gears.)
1975 thru 1987 Overdrive 3.09:1 - 1.67:1 - 1:1 - 0.73:1 (Trucks used a 0.71:1 fourth)
Q: Which is the best ratio 833 4-speed to use in my Slant Six car?
A: It depends on the parts combo you have and what you plan to do with the car. Here is a general overview on how I use the different ratio Chrysler 833 4-speeds:
The OD 833 unit is good for a general purpose street car where you want good off the line (3.09 first) and great highway cruising. (.73 overdrive) I feel these OD units work best with a 3.91 rear end ratio but I bet the new 3.73 ratio offered by Randy's R&P would be a good ratio when used with the OD 4-speed.
(with the 3.73 rear end ratio: 11.53 start-off ratio, 2.72 final drive - OD)
The 3.09 - 1 to 1 final 833 is a good "street / strip" tranny for a Slant Six. Highway cruise starts to suffer with this gear box. Rear end ratio of 3.23 is about as low as I can stand on the highway. I usually run a 2.94 behind this box and put up with the somewhat "lazy" 9.08 start-off ratio that results.
(with the 3.23 rear end ratio: 9.98 start-off ratio, 3.23 final drive - 1 to 1)
The close ratio (2.66 first) tranny is not a good choice for a street slant. These are great for racers, 1/4 mile or road course. You need to run a 3.91 rear to get a 10.40 start-off ratio. (that new 3.73 ratio now offered gives a 9.94 start-off) but these low rear end ratios suck on the open road. (suck gas and "ring" your ears) The "super-close ratio" 2.47 "TA box" is even worse when it come to getting the car to move from a standing start.
Here are the start-off ratio calculations: (2.47 x 3.91 = 9.65 start-off ratio) and (2.47 x 3.55 = 8.77 . . .)
Note: as a general "rule of thumb" a 10 to 1 start-off ratio is pretty good for a "street - strip" Slant Six
Doug Dutra
More on 833 ratios and applications http://www.slantsix.org/articles/4-speeds/applications/options.htm
1964 thru midyear 1966 A-body 3.09:1 - 1.92:1 - 1.40:1 - 1:1 = G/RG and LA engines. (These all used a 4.35" IBR.)
1964 thru 1970 B/RB engine 2.66:1 - 1.91:1 - 1.39:1 - 1:1 = (The "close ratio" V8 gearbox)
1970 T/A & AAR 340s 2.47:1 - 1.77:1 - 1.34:1 - 1:1, = 1970 thru 1974 high performance
(A 2.44 first gear was also produced in this time period and some units had 1.91:1 second gears.)
1975 thru 1987 Overdrive 3.09:1 - 1.67:1 - 1:1 - 0.73:1 (Trucks used a 0.71:1 fourth)
Q: Which is the best ratio 833 4-speed to use in my Slant Six car?
A: It depends on the parts combo you have and what you plan to do with the car. Here is a general overview on how I use the different ratio Chrysler 833 4-speeds:
The OD 833 unit is good for a general purpose street car where you want good off the line (3.09 first) and great highway cruising. (.73 overdrive) I feel these OD units work best with a 3.91 rear end ratio but I bet the new 3.73 ratio offered by Randy's R&P would be a good ratio when used with the OD 4-speed.
(with the 3.73 rear end ratio: 11.53 start-off ratio, 2.72 final drive - OD)
The 3.09 - 1 to 1 final 833 is a good "street / strip" tranny for a Slant Six. Highway cruise starts to suffer with this gear box. Rear end ratio of 3.23 is about as low as I can stand on the highway. I usually run a 2.94 behind this box and put up with the somewhat "lazy" 9.08 start-off ratio that results.
(with the 3.23 rear end ratio: 9.98 start-off ratio, 3.23 final drive - 1 to 1)
The close ratio (2.66 first) tranny is not a good choice for a street slant. These are great for racers, 1/4 mile or road course. You need to run a 3.91 rear to get a 10.40 start-off ratio. (that new 3.73 ratio now offered gives a 9.94 start-off) but these low rear end ratios suck on the open road. (suck gas and "ring" your ears) The "super-close ratio" 2.47 "TA box" is even worse when it come to getting the car to move from a standing start.
Here are the start-off ratio calculations: (2.47 x 3.91 = 9.65 start-off ratio) and (2.47 x 3.55 = 8.77 . . .)
Note: as a general "rule of thumb" a 10 to 1 start-off ratio is pretty good for a "street - strip" Slant Six
Doug Dutra
340mopar
Sorgermotorsports
In '75 there is also a non-OD trans that had a 3.09 first gear.
All early "A" 4 speeds had the 3.09 first gear.
Chuck
All early "A" 4 speeds had the 3.09 first gear.
Chuck
I've driven the Red Challenger that is pictured on article. It had a 2.66 first gear and was powered by a slant six. It wasn't the best combo, clutch slippage to get off the line and then it would spin the engine a little fast going down the freeway.
The green car is a lot for fun, 340 auto. I still get smoke the tires every so often.
The green car is a lot for fun, 340 auto. I still get smoke the tires every so often.
340duster
Well-Known Member
2.66:1 - 1.91:1 - 1.39:1 - 1:1
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