roccodart440
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This is what I use. For my car which has 4.56's and a 28" tire it's on within 50rpm.
Reilly MotorSports, Inc. ::...
3.55's 4.10's or 4.56's?
- Thread starter Shainesboostin
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This is what I use. For my car which has 4.56's and a 28" tire it's on within 50rpm.
Reilly MotorSports, Inc. ::...
4.10 would probably be the gear you would need for the 1/4 mile and 4.56 for 1/8.
Since it's a street car depends what your willing to live with, I don't much highway driving so I'd go 4.10. And 4.10 would give about the same torque to the ground as a 3.55 408.
Since it's a street car depends what your willing to live with, I don't much highway driving so I'd go 4.10. And 4.10 would give about the same torque to the ground as a 3.55 408.
roccodart440
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It would have to be one hella fast car to need 4.56's in the 1/8 mile
I can't even pull 4.56's in the 1/8 mile with my 440 dart
I can't even pull 4.56's in the 1/8 mile with my 440 dart
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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leave the 3.55s.
They are even nearly the right gears to try the qtr;trapping at the top of second.They won't get you low ET, but they will generate a pretty good mph number. The 4.10s are all wrong for a stockish engine with bolt-ons. The 5.9 might go mid-to high ninties. And she might want to trap at 5800. That generates a 4.56 or better.Or 3.23s to 3.55s in second.
So leave the 3.55s, and put a little stall into it instead
4.56 x 2.45 = 11.17. That's a pretty high starter gear with a hi-stall TC, for street duty, with a hi-torque 5.9(small-cammer),making a 1-2 shift just through the intersection, at about 20mph. I never liked it.
With a manual tranny this is a good gear, cuz there is no torque multiplication going on in the TC. I run 10.97 starter gear with a stick and it is already almost too much. But the 1-2 split is 62%, so it is just right going into second.
Your 904 has a 1-2 split of 59%, and a TC ratio adding another estimated 10% or so,and your engine may be making a bit more torque down there than mine does; therefore 3.91/4.10s would be real nice. But they are all wrong for the qtr.
So I say;leave the 3.55s until you figure stuff out. They have been a great street-gear for me.And I tried pretty much all of them.
On the street,First gear should always get you into the bottom edge of the fat part of your torque band at about 32 mph, so that when you nail it from a cruser gear, and it downshifts into first, KABLAM!, it explodes in acceleration. 3.55s will get you around 3460 at 32 with 27s, which, with a stock cam, is just about right. I like First gear to top out at about 62.This is about 6700rpm with 3.55s. If you don't have the cam for that, you will have to shift. And if you are stuck with a stock TC, your engine will fall on it's face while the chebby-pilot motors on by you.So if your 5.9 wants to be shifted at 5500/51mph then it will drop to 3260ish into second. So she better be making some torque down there, to climb outta that hole. Or you can put a bigger TC behind it, and fake it.
So the point I'm trying to make is this; try the 3.55s and see.
Oh yeah, don't forget about the wide ratio 904 with it's 2.74/1.54/1.00 ratios, which is perfect for a low-rpm,hi-torque engine; and 3.55s.
They are even nearly the right gears to try the qtr;trapping at the top of second.They won't get you low ET, but they will generate a pretty good mph number. The 4.10s are all wrong for a stockish engine with bolt-ons. The 5.9 might go mid-to high ninties. And she might want to trap at 5800. That generates a 4.56 or better.Or 3.23s to 3.55s in second.
So leave the 3.55s, and put a little stall into it instead
4.56 x 2.45 = 11.17. That's a pretty high starter gear with a hi-stall TC, for street duty, with a hi-torque 5.9(small-cammer),making a 1-2 shift just through the intersection, at about 20mph. I never liked it.
With a manual tranny this is a good gear, cuz there is no torque multiplication going on in the TC. I run 10.97 starter gear with a stick and it is already almost too much. But the 1-2 split is 62%, so it is just right going into second.
Your 904 has a 1-2 split of 59%, and a TC ratio adding another estimated 10% or so,and your engine may be making a bit more torque down there than mine does; therefore 3.91/4.10s would be real nice. But they are all wrong for the qtr.
So I say;leave the 3.55s until you figure stuff out. They have been a great street-gear for me.And I tried pretty much all of them.
On the street,First gear should always get you into the bottom edge of the fat part of your torque band at about 32 mph, so that when you nail it from a cruser gear, and it downshifts into first, KABLAM!, it explodes in acceleration. 3.55s will get you around 3460 at 32 with 27s, which, with a stock cam, is just about right. I like First gear to top out at about 62.This is about 6700rpm with 3.55s. If you don't have the cam for that, you will have to shift. And if you are stuck with a stock TC, your engine will fall on it's face while the chebby-pilot motors on by you.So if your 5.9 wants to be shifted at 5500/51mph then it will drop to 3260ish into second. So she better be making some torque down there, to climb outta that hole. Or you can put a bigger TC behind it, and fake it.
So the point I'm trying to make is this; try the 3.55s and see.
Oh yeah, don't forget about the wide ratio 904 with it's 2.74/1.54/1.00 ratios, which is perfect for a low-rpm,hi-torque engine; and 3.55s.
Last edited:
roccodart440
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This /\ /\ /\
I'm actually trapping 6200 in 2nd+OD in the 1/8th because I can't pull the 4.56's at 660ft.
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