Built 273, what sure grip ratio with a A833 3.09 first gear

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stroker402

stroker402

1968 dart GTS convertible
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65 barracuda formula S streeter built 300 hp 273
9.5 compression 920 heads
ld340 intake manifold intake ports matched to heads
holley dp 650
1 5/8 semi fender well hooker headers
2.5 head pipes to flowmasters,
a A833 4 speed 3.09 low first gear
3.55 rear gears
Erson solid cam short dur. high lift. 510 lift , 286 duration advertised , 2000-7000 rpm range
72*overlap. Pretty snotty cam for a 273 teener. built similar to the 66 d-dart or 65 golden commando's barracuda "gold fish" specs .
Question is :
would there be any advantage going to a 3.91-4.10 rear gear ratio.
The starter gear with the present 3.55 ratio is 10.9 . 26" tall tire being used . I have to shift pretty quick with a 3.55 gear already. 4.10 would be Really be quick and has no advantage IMO . I'd like to take it on the freeways with 26" tall tires . It's not a race car by any means .
what are your opinions ?
video of 273 with open headers www.youtube.com/edit?o=U&video_id=Lur52zZxN9Y
Thanks .
 
Not sure how comparable this would be but for reference on my 340 4 speed with A833 which i believe has the low first gear and i have 3:55s in the rear with a 28” tall rear tire i run around 55 mph in 4th at 2k rpms
 
stroker402 said:
65 barracuda formula S streeter built 300 hp 273
9.5 compression 920 heads
ld340 intake manifold intake ports matched to heads
holley dp 650
1 5/8 semi fender well hooker headers
2.5 head pipes to flowmasters,
a A833 4 speed 3.09 low first gear
3.55 rear gears
Erson solid cam short dur. high lift. 510 lift , 286 duration advertised , 2000-7000 rpm range
72*overlap. Pretty snotty cam for a 273 teener. built similar to the 66 d-dart or 65 golden commando's barracuda "gold fish" specs .
Question is :
would there be any advantage going to a 3.91-4.10 rear gear ratio.
The starter gear with the present 3.55 ratio is 10.9 . 26" tall tire being used . I have to shift pretty quick with a 3.55 gear already. 4.10 would be Really be quick and has no advantage IMO . I'd like to take it on the freeways with 26" tall tires . It's not a race car by any means .
what are your opinions ?
video of 273 with open headers www.youtube.com/edit?o=U&video_id=Lur52zZxN9Y
Thanks .
Click to expand...
Sounds like you are concerned about your short shift into second. A 3.23 would be logical choice or a taller tire or the tranny that 71dodge demon has which should have the regular first gear. You jave a pretty nasty 273 that is going to need to rev. Second and 3rd will be your power gears. First will be too short and kind of a waste.
 
toolmanmike said:
Sounds like you are concerned about your short shift into second. A 3.23 would be logical choice or a taller tire or the tranny that 71dodge demon has which should have the regular first gear. You jave a pretty nasty 273 that is going to need to rev. Second and 3rd will be your power gears. First will be too short and kind of a waste.
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Yes Mike , with the 3.09 low 1st gear and more gear than 3.55 gear that 1st to 2nd is too quick and does nothing but spin the tires. I never thought of going lower than 3.55 . That starter gear calculation would be way too low and out of the range recommended. If I went with 27" tall tire or 3.23 gear ratio the rpm drop from 1 to 2 would be drastic . not good .
the earlier A833 67 and up is a close ratio not like the one I have (A833 4 speed 1965 ).
Yes, my 273 does rev very nicely , 6500 easily . It sounds Nasty !
 
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Sorry didnt know they made a early a833 with a lower first gear. I couldnt imagine it, 1st in my 68’ a833 in my demon is pretty short to me but i couldnt imagine shorter than that. So is it almost likea a granny lo gear?
 
71DodgeDemon340 said:
Sorry didnt know they made a early a833 with a lower first gear. I couldnt imagine it, 1st in my 68’ a833 in my demon is pretty short to me but i couldnt imagine shorter than that. So is it almost likea a granny lo gear?
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Yes it is .
 
71DodgeDemon340 said:
Sorry didnt know they made a early a833 with a lower first gear. I couldnt imagine it, 1st in my 68’ a833 in my demon is pretty short to me but i couldnt imagine shorter than that. So is it almost likea a granny lo gear?
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Yes .
Here is video I found which sounds like a low first gear mopar or just a lot of rear gear . This is what I am talking about ..www.youtube.com/watch?v=58SfM0fQlcY
 
Huh tgats crazy low, is he even using tge clutch or is he powershifting or what? I dont have the balls to do that in mine lol, way too expensive to fix a mistake, especially without a rev limiter one missed shift and you are done
 
71DodgeDemon340 said:
Huh tgats crazy low, is he even using tge clutch or is he powershifting or what? I dont have the balls to do that in mine lol, way too expensive to fix a mistake, especially without a rev limiter one missed shift and you are done
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Believe it's a lenco 4 speed , just use the clutch once to get it moving and then shift straight back and forth pattern , gas pedal to the floor . Yeah !!!!!!!!!!
 
Thats what i was thinking, couldnt really see his left foot so wasnt sure if he was even using the clutch, i think its the same trans they use in some entry level stock cars
 
If your will to go more rear gear, Id swap the tranny for a later model higher 1st gear so you can go 4.10 plus. And get the benefit of more gearing on all gears instead of just 1st.
 
273 said:
If your will to go more rear gear, Id swap the tranny for a later model higher 1st gear so you can go 4.10 plus. And get the benefit of more gearing on all gears instead of just 1st.
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That would be nice but I have to go with what I have $$$$$.
 
stroker402 said:
That would be nice but I have to go with what I have $$$$$.
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I had a similar 273, even a little crazier, and original 3.09 first gear trans in a 64 Barracuda. Try a set of 3.23 gears, probably the best all around gears. I tried 4.10’s once. After a month or two they were out and sold.
 
66fs said:
I had a similar 273, even a little crazier, and original 3.09 first gear trans in a 64 Barracuda. Try a set of 3.23 gears, probably the best all around gears. I tried 4.10’s once. After a month or two they were out and sold.
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with that 4.10 gear , how did it react to starting out in 2nd gear? I bet that car ran like a raped ape with 4.10's .
 
What is nice about a 26" tall tire (kinda short in height) is you dont need alot of gear to go fst.
If you are just driving the car around to have fun - in this day in age... unless you are track bound
a 273 has alot of ump and does not need deep gears to spin up in that light of a car. 3.55 is still alot of gear with 26" tall tires.
If you have the 69 A-833 with the really low 1st gear, she will still come out of the hole strong with 3.23. BUT top end will still be there so the poor engine is not spinning at top RPM for a simple highway cruise.
Just my opinion. My 72 Demon has the low gear set A-833 trans and 3.91 and a 26" tire and highway is kinda steep, engine screaming.
I had 3.23 and she pulled nice with little over rev at 70mph. I changed to go to the track and just have not swapped back to the 3.23SG chuck.

Joe
 
To clear up the hype (or mis-information)


Capture.PNG
 
stroker402 said:
with that 4.10 gear , how did it react to starting out in 2nd gear? I bet that car ran like a raped ape with 4.10's .
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I never tried starting in 2nd gear. It spun the tires all through 1st and 2nd gear. I was not fast enough to shift first to 2nd, it was at redline almost instantly.
 
You might just have to experiment with real life conditions. I ran the 3.09 low gear in my 273 bracket racer, but it was quicker with the 2.65 low gear. We are talking 4.56 rear end ratio, though. I would suggest trying the 3.23 as a starting point, if you contemplate freeway cruising.

65 Valiant5.jpg
 
66fs said:
I never tried starting in 2nd gear. It spun the tires all through 1st and 2nd gear. I was not fast enough to shift first to 2nd, it was at redline almost instantly.
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www.youtube.com/edit?o=U&video_id=0Wn9TYjzfZo

here is a little video of my car with current stock setup. 3.09 4 speed 26" tire and 3.55's . AS you can here , it just annilates the tires thru 1st gear . It almost sounds like it does need more that 3.55 gears when shifting thru the other 3 gears . That was approx 40 mph when I shifted to 4 gear. I just bagged it in first gear only as you can hear.
 
Yeah a
dibbons said:
You might just have to experiment with real life conditions. I ran the 3.09 low gear in my 273 bracket racer, but it was quicker with the 2.65 low gear. We are talking 4.56 rear end ratio, though. I would suggest trying the 3.23 as a starting point, if you contemplate freeway cruising.

View attachment 1715143001
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Yeah , At the track and slicks on ,you would have to shift as soon as your right foot hit the floor. LOL
I bet with 4.10's and a low first gear , I could start out in 2nd gear just shifting normal ,stop and go lights . I would eliminate one shift . hummmmmmm lol
 
I have the 3.09x3.55 combo and It's perfect for me , Street 367@400hp. I have run that box with a lotta different chunks, and the 3.55s IMO are the best. It takes off like 4.11s with the 2.66 box. The 360 has plenty of torque to pull the 1-2 split, and 3.55s leave me with something for the hiway. My 367 could easily pull 3.23s, but the 3.55s trap better in the 1/8th I think,lol.
Sounds like you need more traction........as do I.
 
stroker402 said:
Yeah a

Yeah , At the track and slicks on ,you would have to shift as soon as your right foot hit the floor. LOL
I bet with 4.10's and a low first gear , I could start out in 2nd gear just shifting normal ,stop and go lights . I would eliminate one shift . hummmmmmm lol
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3.09 x 3.55 = 10.97
1.92 x 4.10 = 7.87

Thats a huge drop. Probably fix your traction problem lol. You be better of fixing your traction problem than swapping gears.
 
273 said:
3.09 x 3.55 = 10.97
1.92 x 4.10 = 7.87

Thats a huge drop. Probably fix your traction problem lol. You be better of fixing your traction problem than swapping gears.
Click to expand...
I agree ! I have a pair g78x14 26" tall, Snow tires I'm going to install this spring and see how they hook . heard rumors that snow tires hook fairly well on the street or track. They have been in my basement for 50 years and still look like new , nice and soft still. should be interesting. I just want to burn m up !
 
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