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727 1st gear ratio

Belle66

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Been searching on Google for a 1st gear ratio higher than 2.45 and haven't found such a thing. Any of y'all know if there is such a thing? Somewhere in the 3 to 3.5 range would be ideal.
Thanks in Advance,
Joel
 
Been searching on Google for a 1st gear ratio higher than 2.45 and haven't found such a thing. Any of y'all know if there is such a thing? Somewhere in the 3 to 3.5 range would be ideal.
Thanks in Advance,
Joel
There is a 2.77 low gear set available. Pro Trans makes a large variety of gear sets but be prepared. Why do you want this? 2.45 or 2.77 is usually plenty of 1st gear.
 
Changing gear sets in a auto is expensive. So is a trans swap. Some folks do a 700R4 swap. Gets you a 3.06, 1.63, 1.00, and 0.7 (for improved mileage, of course).
 
There is a 2.77 low gear set available. Pro Trans makes a large variety of gear sets but be prepared. Why do you want this? 2.45 or 2.77 is usually plenty of 1st gear.
My daily driver also runs street n strip and maybe soon the footbrake class for money. In the book How To Hook N Launch, there is a method of using 1st gear ratio and differential gear ratio and car weight to determine the best starting line ratio. I've got 3.23 rear gear. Rather than change that to something closer to a 4.11, I thought changing 1st in the 727 would be the way to more consistent and faster 60' times. The book indicates that the closer to the starting line ratio, the more consistent 60' and ET.
 
Changing gear sets in a auto is expensive. So is a trans swap. Some folks do a 700R4 swap. Gets you a 3.06, 1.63, 1.00, and 0.7 (for improved mileage, of course).
Thanks for the information and the heads up on cost.
 
A standard 2.45 will hit the tires hard enough. A little more rear axle gear is easier. Tork converter selection a main key. Really depends on what your use is.
 
My daily driver also runs street n strip and maybe soon the footbrake class for money. In the book How To Hook N Launch, there is a method of using 1st gear ratio and differential gear ratio and car weight to determine the best starting line ratio. I've got 3.23 rear gear. Rather than change that to something closer to a 4.11, I thought changing 1st in the 727 would be the way to more consistent and faster 60' times. The book indicates that the closer to the starting line ratio, the more consistent 60' and ET.

On the whole, rear gears are definitely less expensive than changing AT gearing. There are many on-line calculators that help you determine the most cost-effective solution for your desires. I would look at overall tire diameter as a potential cost-effective way to achieve your goals. If it were a dedicated race car I'd even leave the trans as it is and futz with rear gear/tire combo pkgs depending on 1/4 or 1/8 mile, which ever I ran more often. Tires/wheels are cheaper and less messing than those things that contain fluid. As a daily driver, the 3.23 rear is a good ratio. Keep us updated on what you come up with.
 
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Thanks for the information and the heads up on cost.
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What does your car weigh? The low gear sets are usually used in heavier cars and the cut off is about 3000 lbs.
 
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What does your car weigh? The low gear sets are usually used in heavier cars and the cut off is about 3000 lbs.
It's a stock 66 Belvedere II around 3800#. Just musing over what the next steps may be to improve performance and keep it primarily a daily driver.
 
Word to the wise.....
If you are happy with your "daily driver" and want to run it at the drag races, just buy a set of slicks that will fit nicely into your stock wheel wells and go racing.
Whatever it runs, it runs.
You will be bracket racing anyway, so just dial in at what it runs and have a good time..
Once you start down the road for "more performance, lower ET's, etc, it is a NEVER ENDING EXPENSE.
So, if ur car runs, let's say 12.75 ET now, why spend a couple thousand dollars to make it run 12.30's. You will feel better, maybe, but you will just as likely to win your bracket class running 12.75 as running 12.30.
Just get a set of slicks and go racing.
Get seat time at the drags, improve your reaction time by seat time and your car will probably run the basically the same number about everytime, depending on the weather.
I think most everyone here will agree with me.
Now....if you really want to go FAST, just prepare to spend about $15,000 to $20,000 for a big motor, race trans with transbrake, Narrowed, race Dana, race headers, race fuel pump system, race ignition, shifter, batteries, battery charger, etc, etc,....it is endless.
I have gone this way and don't regret it, but I could have had "fun" with my car as it was....a 12.20et car at the track, just the way it was when I bought it.
 
It's a stock 66 Belvedere II around 3800#. Just musing over what the next steps may be to improve performance and keep it primarily a daily driver.

I believe your Belvedere II is closer to 3300 pounds.
 
I'M RUNNING 727 MILD STALL,(200 RPM ABOVE STOCK) 3:23, 255 X 60 15 MICKEY THOMPSON DRAG RADIALS ON A MAGNUM 500 RIM WITH 4 1/2" BACK SPACE THIS TIRE FITS AND HOOKS. FOR STREET/ STRIP THESE TIRES ARE PERFECT

4-_DSC3152.JPG _DSC8925-001.JPG
 
A looser converter will help. Take a look at Power Glide 1st gear ratios. 1.76 or 1.82 for prodution. Many people race with these. Is 3.23 going to be the quickest? No, but that doesn't mean you can't race it. The 3.06 with a 3.23 would be very close to 2.45 with a 4.10 . But is it worth expense?
Doug
 
My last comment to to the OP, a 2.77 low 727 gear is an expensive solution to the issue and may not provide any significant improvement. A really good torque converter for your combination will produce better results at a far lower cost. Good luck.
 
If you're trying to calculate the vehicle weight, here are the source I looked at. Whether its right or not...

http://www.classiccardatabase.com/specs.php?series=8174&year=1966&model=33625

The 727 is geared well, the stock converter has a decent stall range for a daily driver and some track fun. As stated above, you could improve on the converter. Changing the rear gears to 3.55 wouldn't kill the daily driver aspect too bad, and will improve the track aspect.

A good daily driver is not a really a good track car, and a good track car is really not a good daily driver. Somewhere in the middle you'll have a car that's "acceptable" as both, but is a heck of a lot of fun.

Good luck.
 
If you were to go with a low gear set with 3.23: 1st gear would act like a 3.6 rear gear, 2nd gear would be like a 3.4 rear gear and your drive would be back to 3.23.

I installed the low gear set with a 4.10 rear gear and the changes for me work out to be like 4.58 1st, 4.35 2nd, and 4.10 for third.
 
I have a pushbutton trans that is supposed to have a 2.77 gear set in it. Is there any way to find out for sure without ripping the trans apart?
 
I have a pushbutton trans that is supposed to have a 2.77 gear set in it. Is there any way to find out for sure without ripping the trans apart?
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Sounds like the transmission that came with my car. I found out what was in it when I took it apart. I believe that to be sure you pretty much need to open it up, unless you have an idea of your rpm / speed of your car with a standard gear ratio to compare to. And yeah, my trans has a billet set like I was told, but I had to put it in order to get it.
 
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