Is a 4.30 rear end right for me?
#104684
08/14/08 10:56 AM
08/14/08 10:56 AM
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Joined: Mar 2003
Posts: 4,930 Tri-Cities, Washington
VITC_GTX
OP
master
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OP
master
Joined: Mar 2003
Posts: 4,930
Tri-Cities, Washington
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1970 GTX, original 440/727. Has the old 284/484 purple cam. Stock compression forged pistons, ported 906's shaved 0.020", FBO ignition, Eddy intake, Holley 750 DP. I currently have a 3.55 but have very little low end power with this cam. I'm sure the torque converter is part of the problem but I plan on replacing that too. I drive the car 100% street with most of that in town. When I hit the highway I am content driving 60 mph.
So, with this motor what would you think about dropping in a 4.30 and a converter that flashes about 2800???
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Re: Is a 4.30 rear end right for me?
[Re: VITC_GTX]
#104685
08/14/08 11:03 AM
08/14/08 11:03 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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i love my 4.30's. especially with the 284/484 cam.
put a higher stall converter in it and LET ER RIP! You'll say "YEEEEEEEEEEEEEEHAAAAAAAAAAAAAAA!"
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Re: Is a 4.30 rear end right for me?
[Re: buildanother]
#104687
08/14/08 11:08 AM
08/14/08 11:08 AM
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Joined: Jan 2003
Posts: 70,126 Here
DirectSubjection
Tacohead. The First and Only
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Tacohead. The First and Only
Joined: Jan 2003
Posts: 70,126
Here
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Swap the convertor first, then see if you like the results before putting in gears.
Ride eternal, shiny and chrome
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Re: Is a 4.30 rear end right for me?
[Re: buildanother]
#104692
08/14/08 12:10 PM
08/14/08 12:10 PM
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Joined: Dec 2003
Posts: 1,400 Columbia Station, Ohio
69RTSE
pro stock
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pro stock
Joined: Dec 2003
Posts: 1,400
Columbia Station, Ohio
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Quote:
I would get a 10 inch converter in there and leave the rear alone.
Quote:
Swap the convertor first, then see if you like the results before putting in gears.
I have a Comp cams .507/.510 lift hydraulic cam, iron heads with big valves, TM7 intake and 750 BG carb, 3400 converter. With slicks and 4.10s in my 69 Charger I went 12.20s. With street tires (275/60-15 GY Eagle Sts) and 3.23s it went 12.80s. I really like the 3.23s now, great for cruising. Don't forget a tranny cooler with the higher stall converter.
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Re: Is a 4.30 rear end right for me?
[Re: MoparforLife]
#104697
08/14/08 01:13 PM
08/14/08 01:13 PM
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Joined: Oct 2003
Posts: 11,684 W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,684
W. Kentucky
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Quote:
For 100% street driving you will be much happier with a 3.91 than a 4.30. 4.30 is pretty deep for a street car. 3.93 at 60 mph will spin your engine approx. 3000. 4.30 alot more than that.
My small block Dart had 3.91s in it and I went to 4.30s and saw very little difference in et, something like .06 in 60' IIRC. On the street I can tell a huge difference, I run 275/60 ET Streets. Power braking will not tell you the stall of you're converter. At a slow speed in high gear floor board it, the tach will flash to the converters stall rpm. My 9.5" 4400 will only power brake to about 2800 rpm.
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Re: Is a 4.30 rear end right for me?
[Re: AdamR]
#104702
08/14/08 03:21 PM
08/14/08 03:21 PM
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Joined: Nov 2003
Posts: 4,027 Dearborn Hts, MI
Sledge_57
master
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master
Joined: Nov 2003
Posts: 4,027
Dearborn Hts, MI
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I like my 4.30's however if I wanted to drive 60mph on the freeway I'd go back to 3.91 Mines spins 3000 at 50mph with 275-60-15 tires and a 9 1/2" PTC 4200 converter. Cruisin at 60mph ain't happening for me with the 4.30's
Doug
1967 "Pedal Car" 500" low deck , TF 727, 4.30 Locker Best to Date: 11.67 @ 114.9 1.64 60ft
"Kids in cars cause accidents. Accidents in cars cause kids..."
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