1966newport
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its a dog off the line with the stock 2.76 gears. What can i change too without hi rpm at 70? and i m got putting in over drive.
66 newport with 69 hp 440
- Thread starter 1966newport
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It’s a give and take. The 2.76 you are giving from standing start.
how tall are the rear tires?
I like 3.23 gears if the tires are 27”-28” tall. I like 2.9 gears of the rear tires are 26” or shorter.
i like to remove 2.76 gears and not use them.
how tall are the rear tires?
I like 3.23 gears if the tires are 27”-28” tall. I like 2.9 gears of the rear tires are 26” or shorter.
i like to remove 2.76 gears and not use them.
commando1
Old Man with a Hat
3.23
69CoronetRT
Senior Member
The snarky answer is an A body.
You have a heavy C body. Newton's first law applies.
What are your REALISTIC expectations of performance?
Life is full of trade offs. Do you really want off the line pick up or no RPMs at 70?
3.23 gears were stock for a reason. They are a simple compromise but I don't think you'll notice that much difference from a 2.76.
Do the math so you can see the difference in numbers.
It is just like using a longer breaker bar on a tight bolt, makes it easier to move.
First gear in a 727 is 2.45. Multiply by rear gear ratio.
2.76x2.45=6.76
3.23x2.45=7.91
many want to have a 3.55 ratio
3.55x2.45=8.69
Now do you see what’s happening here?
Use this calculator to see the rpm at any speed you choose Click the dot next to mph and then enter in different rear gear ratios to see MPH
Gear Ratio Calculator - Strange Engineering
It is just like using a longer breaker bar on a tight bolt, makes it easier to move.
First gear in a 727 is 2.45. Multiply by rear gear ratio.
2.76x2.45=6.76
3.23x2.45=7.91
many want to have a 3.55 ratio
3.55x2.45=8.69
Now do you see what’s happening here?
Use this calculator to see the rpm at any speed you choose Click the dot next to mph and then enter in different rear gear ratios to see MPH
Gear Ratio Calculator - Strange Engineering
FIRST thing to do is to inquire about just what your expectations might be and definition of "dog" might be! Even the base 383 2bbl with 2.76 and H78-14 tires will lay some rubber, IF its tuned to factory specs. With the additional low rpm torque of the 440, it should light the tires, even with the stock torque converter, from my experiences.
SECONDLY, even with that extra power, in modern times, almost every non-turbo 4cyl little car with the gazillion-speed automatics will leave our cars sitting still as they are 50' ahead when the light turns green. SO . . . just what is your comparison???
THIRDLY, are you just flooring it from idle or pre-loading things with the foot brake? With the stock converter, as tight as they tend to be (which makes for tighter throttle response at normal driving speeds), the engine speed will not immediately jump nearly as much as it might with a modern 6+ speed automatic with its approx 4.75 low gear ratio.
FOURTHLY, how is the engine tuned? What initial timing and what total mechanical advance in the distributor? Is the distributor stock for the '69 engine or is it correct for the model year of the car? A dwell tach and dial-back timing light can check these things.
So, just what are you seeking to achieve? Just curious. You can trick things with a deeper rear axle ratio and stickier tires, and a few rear leaf spring modifications, but the car is still a 4500 pound vehicle that is moving from rest, which takes TORQUE multiplication in the transmission gears and torque converter, plus the rear axle to make it work as well as it can. I believe that @MEV has a quick '66 New Yorker with some YouTube videos of it in action. A nice car that is quick at the drag strip.
Although that generation of C-body does have a very credible road performance, key word "road", and can do well in drag strip performance, their main forte was higher speed highway travel with ease and comfort (even if the road might not be completely straight and flat), from my experiences. In other words, venues where its weight can be an asset rather than otherwise (as in the "stop light Grand Prix", as it used to be termed).
Personally, being from TX with lots of highways (rural and otherwise), the value of the 2.76 rear axle is apparent as that allows nice cruising in the 75-90mph range (at 70mph, our '66 Newport with HD shocks is bored, but at 75mph, its more like "This is fun. Lets do some more!" But past 90mph, the factory HD replacement shocks needed to be a bit stiffer for best results (with stiffer springs, too). Figure that with the 2.76 and P225/75-15 tires, approx 29mph of road speed per 1000rpm. With a 3.23, approx 25mph of road speed per 1000rpm. With fuel costs what they have been for the past 20 years, having the 2.76 can make financial sense.
Remember, too, that TIRES can make a big difference in off-line feel at high throttle settings. Get some better ones and they don't spin as much. Get some other ones and they spin easier, but will not last as long. More decisions . . .
Just some observations and experiences,
CBODY67
SECONDLY, even with that extra power, in modern times, almost every non-turbo 4cyl little car with the gazillion-speed automatics will leave our cars sitting still as they are 50' ahead when the light turns green. SO . . . just what is your comparison???
THIRDLY, are you just flooring it from idle or pre-loading things with the foot brake? With the stock converter, as tight as they tend to be (which makes for tighter throttle response at normal driving speeds), the engine speed will not immediately jump nearly as much as it might with a modern 6+ speed automatic with its approx 4.75 low gear ratio.
FOURTHLY, how is the engine tuned? What initial timing and what total mechanical advance in the distributor? Is the distributor stock for the '69 engine or is it correct for the model year of the car? A dwell tach and dial-back timing light can check these things.
So, just what are you seeking to achieve? Just curious. You can trick things with a deeper rear axle ratio and stickier tires, and a few rear leaf spring modifications, but the car is still a 4500 pound vehicle that is moving from rest, which takes TORQUE multiplication in the transmission gears and torque converter, plus the rear axle to make it work as well as it can. I believe that @MEV has a quick '66 New Yorker with some YouTube videos of it in action. A nice car that is quick at the drag strip.
Although that generation of C-body does have a very credible road performance, key word "road", and can do well in drag strip performance, their main forte was higher speed highway travel with ease and comfort (even if the road might not be completely straight and flat), from my experiences. In other words, venues where its weight can be an asset rather than otherwise (as in the "stop light Grand Prix", as it used to be termed).
Personally, being from TX with lots of highways (rural and otherwise), the value of the 2.76 rear axle is apparent as that allows nice cruising in the 75-90mph range (at 70mph, our '66 Newport with HD shocks is bored, but at 75mph, its more like "This is fun. Lets do some more!" But past 90mph, the factory HD replacement shocks needed to be a bit stiffer for best results (with stiffer springs, too). Figure that with the 2.76 and P225/75-15 tires, approx 29mph of road speed per 1000rpm. With a 3.23, approx 25mph of road speed per 1000rpm. With fuel costs what they have been for the past 20 years, having the 2.76 can make financial sense.
Remember, too, that TIRES can make a big difference in off-line feel at high throttle settings. Get some better ones and they don't spin as much. Get some other ones and they spin easier, but will not last as long. More decisions . . .
Just some observations and experiences,
CBODY67
Although i have 3.23 gears now, i would be running the stock 2.76 if i could have found a yoke that would work with 1350 size u joints, or a fine splined pinion set of 2.76 gears (they dont exist for 489 cased 8 3/4 rearends that i could find) even with the stock 440 the 2.76's were great. I ran them with the stroker and a detroit locker until i broke the yoke and upgraded to a 1350 sized yoke on both ends of the driveshaft.
It might be better with a better distributor curve. Halifaxhops can help you with that. Make sure everything is in proper tune and working properly.
1966newport
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distrubutor was professionally curved. it runs great but it slower than by /6 dart was
1966newport
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34 total, 10 intiial, all in at 2000
Kind of sounds like they used a common spring kit, to me. Which is more of a "drag racing curve" than not, although it is recommended in the old Direct Connection Race Manuals. I would suggest going to 12 degrees BTDC, provided it doesn't clatter on mild acceleration. But if it won't move quickly at 10 degrees, that extra few degrees will not really change anything.
Check the timing mark on the balancer. Look to see if the outer ring on the balancer has moved outward or rearward in relation to the main hub on the balancer.
Might need to remove the timing cover to verify that the cam sproket is installed correctly and not "one tooth off" or something like that, for verification. That CAN be easy to do, sometimes.
Which carb?
What was done to that Slant 6? Just curious . . .
CBODY67
Check the timing mark on the balancer. Look to see if the outer ring on the balancer has moved outward or rearward in relation to the main hub on the balancer.
Might need to remove the timing cover to verify that the cam sproket is installed correctly and not "one tooth off" or something like that, for verification. That CAN be easy to do, sometimes.
Which carb?
What was done to that Slant 6? Just curious . . .
CBODY67
1966newport
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motor was rebuilt and cam was properly degreed. carb is a 650 thunder series
1966newport
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it rattles at 12 degrees
keithnh
New Member
Have a stocker 4dr Monaco with 383/2bbl. Just trying to get running but bought car with missing driveshaft and carb. Want to see actual trans and motor condition. Not sure why parts missing as nothing looks disrupted underneath. Motor spins fine. Have not ID'd trans yet. Wondering if someone here might be able to help me ID trans and find driveshaft.
Shorter tires would be low-cost fast way to improve pull from stop .. I use tall tires with my 2.73 locked-posi enduro car to multiply my big block advantage at lower rpms near peak efficiency in roundy-round racing, 1st to 5000rpm for bursts mainly use 2cnd. Average speeds on short track near 85mph. C-body might look cool "low-rided" abit with short wide fat tires though rpm will be higher per mph. Buy a set of cheap used shortys and check it out before committing.
Could also add nitrous or boost with turbo and keep tires you have but more $
Shorter tires would be low-cost fast way to improve pull from stop .. I use tall tires with my 2.73 locked-posi enduro car to multiply my big block advantage at lower rpms near peak efficiency in roundy-round racing, 1st to 5000rpm for bursts mainly use 2cnd. Average speeds on short track near 85mph. C-body might look cool "low-rided" abit with short wide fat tires though rpm will be higher per mph. Buy a set of cheap used shortys and check it out before committing.
Could also add nitrous or boost with turbo and keep tires you have but more $
Last edited:
mr gtx
Active Member
i think it rattles now and you don't know it that's why no power. big car 276 gear and timing all in at 2000 rpms no way. unless you have 9.1 or less compression. i would not have it come in till 3200 rpms at the lowest.
Gerald Morris
Senior Member
I LIKE the tight ratio of 2.76 or 2.94:1, for the highway, but alas, in town, where 99% of my driving is done, I've found 3.23:1 ideal. Mind you, Mathilda actually could scratch even w her 2-bbl 383 and 2.94:1 rear end, so, I ran around town in 2nd gear plenty.
Perhaps you might install a mild stall converter with your highway gears? A 440 should have NO trouble providing ample torque, even to tight arse rear end gears. Try a good stall converter, optimized for say, 3k RPM, and you should be able to punch your ride around town pretty well.
Also, shift kits exist that might help you optimize when your tranny kicks in the higher gears. 2nd gear gives a ratio of ~1.45:1 if I recall correctly, which makes a good compromise with 2.76:1 on the arse. Do your sums and quotients here, try several differing tire sizes to see how much umph you put to the asphalt.
Wish I had a 440 right now....been looking a bit too, but AZ has been picked over plenty the past 6 yrs.
Perhaps you might install a mild stall converter with your highway gears? A 440 should have NO trouble providing ample torque, even to tight arse rear end gears. Try a good stall converter, optimized for say, 3k RPM, and you should be able to punch your ride around town pretty well.
Also, shift kits exist that might help you optimize when your tranny kicks in the higher gears. 2nd gear gives a ratio of ~1.45:1 if I recall correctly, which makes a good compromise with 2.76:1 on the arse. Do your sums and quotients here, try several differing tire sizes to see how much umph you put to the asphalt.
Wish I had a 440 right now....been looking a bit too, but AZ has been picked over plenty the past 6 yrs.
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