.82 or .64 OD
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
Noones comparing a C3 to a truck it was merely an example of "low rpm" isnt necessarily as beneficial as people think. So many posts youll see on forums where the lower cruise speed they can get the better its simply not true.
On a wheezy l48 with OD a snoring cruise speed will hurt more than help theres simply no torque to pull the car.
On a wheezy l48 with OD a snoring cruise speed will hurt more than help theres simply no torque to pull the car.
Le Mans Master
Joined: Oct 2007
Posts: 7,456
Likes: 977
From: RI, Now Franklin/Nashville TN
Many people cruse at 65 .. You think 80 is the norm .. Maybe in your state it is .. But an O/D only good until you hit 80 is useless ..
With correct gearing for the street a O/D should be doable at 60 .. Your instance 65 is to slow or even 60 is laughable because driving is not exclusive to the highway .
With 3.92 rears my O/D ( automatic) Is perfect from 45 and up.
With correct gearing for the street a O/D should be doable at 60 .. Your instance 65 is to slow or even 60 is laughable because driving is not exclusive to the highway .
With 3.92 rears my O/D ( automatic) Is perfect from 45 and up.
I routinely drive 80 MPH where I am and so is everyone else-70 MPH will get you run over on the highway in the left lane. I drive quite a bit in the southeast US and everyone there is going 75-80 MPH as well as out west. My point is speed enforcement in upstate NY does not appear to be in line with what I have experienced elsewhere even in the Northeast-something for you to consider. When I drive in Upstate NY because of the kill joys, I drive on Cruise at 69 MPH-this on wide open very light traffic roads-it's sort of ridiculous but tough to beat the instant on radar and laser-no choice.
Last edited by jb78L-82; Mar 29, 2014 at 07:55 AM.
Le Mans Master
Joined: Oct 2007
Posts: 7,456
Likes: 977
From: RI, Now Franklin/Nashville TN
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I just came back from your neck of the woods in western NY yesterday-Buffalo for work (flew and rent a car) ,I travel quite a bit to Rochester for work as well, wife from Buffalo and in laws still live there, annual pilgrimage to montreal for F1 race in June-driving from Albany north to Canadian border…. I have quite a bit experience driving in upstate NY and I must say I feel really bad for drivers up there, since the NY State police are BRUTAL with looking for speeders. "Speeders" are >69 MPH in a 65 MPH zone-instant on radar etc. It's insane!
I routinely drive 80 MPH where I am and so is everyone else-70 MPH will get you run over on the highway in the left lane. I drive quite a bit in the southeast US and everyone there is going 75-80 MPH as well as out west. My point is speed enforcement in upstate NY does not appear to be in line with what I have experienced elsewhere even in the Northeast-something for you to consider. When I drive in Upstate NY because of the kill joys, I drive on Cruise at 69 MPH-this on wide open very light traffic roads-it's sort of ridiculous but tough to beat the instant on radar and laser-no choice.
I routinely drive 80 MPH where I am and so is everyone else-70 MPH will get you run over on the highway in the left lane. I drive quite a bit in the southeast US and everyone there is going 75-80 MPH as well as out west. My point is speed enforcement in upstate NY does not appear to be in line with what I have experienced elsewhere even in the Northeast-something for you to consider. When I drive in Upstate NY because of the kill joys, I drive on Cruise at 69 MPH-this on wide open very light traffic roads-it's sort of ridiculous but tough to beat the instant on radar and laser-no choice.
jb78L-82- if you are going to the F1 in Montreal and passing thru Toronto let me know, you can make a pitstop at my place if you like. I can give you the address and my phone number.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
I didn't realize how bad my carb was set up until I switched from an auto to a manual. Boy, was there a lean miss on light throttle changes.
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
Someone with a BB with a .64OD AND real word experience 
Does it "load" up on the highway at 1,800 RPM ????
Does it buck and surge on the highway in overdrive because its a "carb" car and not FI?????
What total nonsense!!!!
Its fine for people to have different preferences about what they want from an OD but misinformation and comments that are simply not true is another story………….
Does it "load" up on the highway at 1,800 RPM ????
Does it buck and surge on the highway in overdrive because its a "carb" car and not FI?????
What total nonsense!!!!
Its fine for people to have different preferences about what they want from an OD but misinformation and comments that are simply not true is another story………….
I recognize the OP has made his decision, just wanted to reinforce what I wrote earlier was from experience, not speculation on something I didn't know about. My driving situation may be different than the OP's in that the speed limit is 70 where I am, so cruising at 75 in traffic is common, but I certainly drove this combination at 65 without any problems.
I'm running a 3.73 and 540 now, but I might have a driving video of the 427/3.08/0.64.
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
Here's a sun-light faded-out video of my 427 Vette with 3.08 rear, 0.64 OD and 275/50/15 shorty tires (25.8" diameter). Sorry to say that I hadn't gotten my speedo repaired at this time, but you'll see that I've gone thru 5 gears and the car is purring along between 1700-1800 rpm, happy as could be at 70 or so.
This is from Photobucket and when I look at the same video on my computer using Windows Media Player it is much brighter and sharper. Too bad I didn't have the GoPro at the time.
BTW, this is with a Holley 800DP, Hooker Sidepipes and STS Baffles.
This is from Photobucket and when I look at the same video on my computer using Windows Media Player it is much brighter and sharper. Too bad I didn't have the GoPro at the time.
BTW, this is with a Holley 800DP, Hooker Sidepipes and STS Baffles.
Last edited by Super6; Mar 30, 2014 at 07:18 AM. Reason: Added "BTW" comment.
Le Mans Master
Joined: Oct 2007
Posts: 7,456
Likes: 977
From: RI, Now Franklin/Nashville TN
Re-read post no. 22 above. I ran a 3.76" stroke 427 big block with a 3.08 rear and the 0.64 OD on 25.8" tires with no problems. The 3.36 with 26" tires has 8% more multiplication, besides the fact that the OP's Vette is a 4" stroke 454. My friend runs a 3.08 with 27" tires and a torquey 468ci with the 0.64 OD on Long Island, where there isn't even a 70 mph speed limit, so he's in OD at 60-65. I could go down to 1300 rpm with the 427 before the engine would get unhappy. Of course, I wouldn't run it there or expect anything but gentle acceleration. I repeat, this is a no brainer for the OP's combination if cruising is the goal and I'm not speculating about it, I ran a "worse" combination.
I recognize the OP has made his decision, just wanted to reinforce what I wrote earlier was from experience, not speculation on something I didn't know about. My driving situation may be different than the OP's in that the speed limit is 70 where I am, so cruising at 75 in traffic is common, but I certainly drove this combination at 65 without any problems.
I'm running a 3.73 and 540 now, but I might have a driving video of the 427/3.08/0.64.
I recognize the OP has made his decision, just wanted to reinforce what I wrote earlier was from experience, not speculation on something I didn't know about. My driving situation may be different than the OP's in that the speed limit is 70 where I am, so cruising at 75 in traffic is common, but I certainly drove this combination at 65 without any problems.
I'm running a 3.73 and 540 now, but I might have a driving video of the 427/3.08/0.64.
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Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
Thanks for pointing out my oversight that you previously posted real world experience with the .64 OD with your BB and seem to endorse using the .64 OD with a BB with 3.08 gears and 26 inch tires. To me, it's a no brainer as well that this transmission with a .64 OD was MADE for a BB, of all engines in the C3, pretty much regardless of the rear end with the rear gears being more relevant for a SBC which generally has less torque, especially down low. The OP has made his decision of that's fine but just want to make sure that others are not misinformed on the benefits of using an OD which is generally for reduced revs, less engine noise, less engine wear, and better MPG and NOT as an acceleration gear which is what the other 4 gears are for in a 5 speed, unless you are road racing.
If the OP was asking the same question, but for a track car, I'd be right there with George and Paul recommending the 0.82 for that application.
Race Director
Joined: Apr 2007
Posts: 11,152
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From: South Western Ontario
Thanks for throwing your clarification into the mix. A worse rear-gear and the combination still worked fine for you. It really does come down to cruising vs racing.
Race Director
Joined: Jan 2000
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From: San Jose CA
Luckily, my wife has allowed me to go the route of increasing torque to solve this problem.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
My 78 is set up pretty awfully for this, actually. I have low static CR and a mild cam, but it means next to no power under 2500. 5th is good for holding at 70+, but if I'm pulling a hill or any slower than that I need to downshift. It's actually pretty aggravating.
Luckily, my wife has allowed me to go the route of increasing torque to solve this problem.
Luckily, my wife has allowed me to go the route of increasing torque to solve this problem.
Le Mans Master
Joined: Oct 2007
Posts: 7,456
Likes: 977
From: RI, Now Franklin/Nashville TN
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
What you meant to say was "If you're running a big block with similar specs to the 454HO, it comes down to whether you're building a cruiser or a road racer", then?
I agree with lionelhutz's statement (with my clarifications
); I don't look at these threads in the context of only the OP's question because I know people will read bits and pieces and come out with an answer such as ".82 is for road racing and .64 is for cruising", I'm running a "cruiser" and the 0.64 S-U-C-K-S for cruising (with MY setup). Tremec calls the .82 gear a "road-race" gear, so hopefully you can see why I'd want to draw a little more light to it.
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
That Video ,,, I have to laugh ,,Driving in traffic on different surfaces varying speed and having a real cruse is not what that video showed. It showed a tach that was staying on one RPM on what is obviously an empty flat road after a somewhat stiff acceleration.
If I want to I can hit O/D at 30 on a flat road with no traffic or hills and let her run down the road at 1100rpm with my small block and it is not proving anything.
A tall rear and a tall O/D are just senseless on any motor with a carb. If it was such a great idea it would have been done in the sixties.
People can do what they want .. But to say it is a great combo and argue that it is just funny.
If it was my car I would have a Min of 3.73 and a max of 4.11 with that o/d not a 3.08 ... That would be doing it right and you would use the O/D in a lot more sensible manor .
If I want to I can hit O/D at 30 on a flat road with no traffic or hills and let her run down the road at 1100rpm with my small block and it is not proving anything.
A tall rear and a tall O/D are just senseless on any motor with a carb. If it was such a great idea it would have been done in the sixties.
People can do what they want .. But to say it is a great combo and argue that it is just funny.
If it was my car I would have a Min of 3.73 and a max of 4.11 with that o/d not a 3.08 ... That would be doing it right and you would use the O/D in a lot more sensible manor .
Le Mans Master
Joined: Jan 2003
Posts: 6,575
Likes: 1
From: Tuttle OK
Cruise-In VIII Veteran
That Video ,,, I have to laugh ,,Driving in traffic on different surfaces varying speed and having a real cruse is not what that video showed. It showed a tach that was staying on one RPM on what is obviously an empty flat road after a somewhat stiff acceleration. If I want to I can hit O/D at 30 on a flat road with no traffic or hills and let her run down the road at 1100rpm with my small block and it is not proving anything.
Alrighty then…
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
Honestly with a big block and 3.08 your are perfectly ok with a 4 speed, but if you want more performance and economy then up the rear gears and pick the O/D ratio accordingly. Other wise it is a mis-match. It is a compromise and a different driving experience that adds no performance and that is my point , at least with the deeper O/D , the gear is not so tall as to alter existing driving habits. It is not so tall that O/D becomes highway only gear.
Lower RPM does not equal better MPG .. Nor does it make the engine less stressed. If it is mismatched then your making bad changes.
Anyone can make a bad change but a good change is always worth the extra effort.
By 50mph he can hit 5th ... And accelerate comfortably in traffic . With .64 he is not going to really want to use 5th gear .. Well unless he is on an open flat vacant road and higher speeds.
Lower RPM does not equal better MPG .. Nor does it make the engine less stressed. If it is mismatched then your making bad changes.
Anyone can make a bad change but a good change is always worth the extra effort.
By 50mph he can hit 5th ... And accelerate comfortably in traffic . With .64 he is not going to really want to use 5th gear .. Well unless he is on an open flat vacant road and higher speeds.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
As for any others, if they believe statements about the combo being questioned in this thread applies to any combo then that's their problem. I'd rather not muddy up an answer by covering every possible drivetrain combination scenario.
If you're going to say your combo doesn't work then list your combo. Your combo is quite different than the one in question so your experience doesn't apply very well to the question asked in this thread, but since you were posting your experience at least give enough details that someone reading might find it interesting and helpful to their application.
Last edited by lionelhutz; Mar 30, 2014 at 09:08 PM.
Racer
Joined: Feb 2014
Posts: 405
Likes: 12
Geeez guys all over a OD ?
But my 2013 Silverado gets 22 mph and its a brick and weighs a ton ....... Just joking with yah and really dont care about any of this but it will. Flow master duals, air raid intake tube and filter.
Ive got 28 mpg with my C3 with a crate motor 308s with 4 speed at 67 mpg
Big motors can lug along just fine, but with I with a carb it gets down to the proper tune, cam combination and ignition timing / curve
All done with this one
Cheers Dale
67 MPH ........LOL
But my 2013 Silverado gets 22 mph and its a brick and weighs a ton ....... Just joking with yah and really dont care about any of this but it will. Flow master duals, air raid intake tube and filter.
Ive got 28 mpg with my C3 with a crate motor 308s with 4 speed at 67 mpg
Big motors can lug along just fine, but with I with a carb it gets down to the proper tune, cam combination and ignition timing / curve
All done with this one
Cheers Dale
67 MPH ........LOL
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
If you read my previous responses I already described how the application originally postedt comes down to feel. More rpm and more throttle response or lower rpm and more likely having to downshift to really accelerate. But no-one bothers to read so I couldn't be bothered writing that out yet again and wrote racing vs cruising instead.
As for any others, if they believe statements about the combo being questioned in this thread applies to any combo then that's their problem. I'd rather not muddy up an answer by covering every possible drivetrain combination scenario.
If you're going to say your combo doesn't work then list your combo. Your combo is quite different than the one in question so your experience doesn't apply very well to the question asked in this thread, but since you were posting your experience at least give enough details that someone reading might find it interesting and helpful to their application.
As for any others, if they believe statements about the combo being questioned in this thread applies to any combo then that's their problem. I'd rather not muddy up an answer by covering every possible drivetrain combination scenario.
If you're going to say your combo doesn't work then list your combo. Your combo is quite different than the one in question so your experience doesn't apply very well to the question asked in this thread, but since you were posting your experience at least give enough details that someone reading might find it interesting and helpful to their application.
I'm not sure if I'm happy here or would have been happier with the .82. We'll see how I feel after I get my new engine in.
ALL of that said, I think if I were to do it all over I'd go with a T56, so that I'd have something that wasn't a complete dog between 40 and 60, but wasn't taching 3k+ like 4th is. Hopefully my next iteration solves that.
I think this engine would have been happier cruising in 5th if I'd left it alone (the GW350 is basically an L48, lots of grunt). Oh well.