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3.50 or 3.70 for my 9" ??

  • Thread starter Thread starter Irish_AL06
  • Start date Start date Feb 8, 2006
I

Irish_AL06

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Feb 8, 2006
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Feb 8, 2006
#1
  • Feb 8, 2006
  • #1
Hey all,

Im planning on running a ford racing 345 hp crate with a t-5z in my 65 coupe... Im looking for a decent around town drive but I dont want it to be a dog at the back roads drag race.

Thanks for your help.
 

66ford289

New Member
Apr 10, 2005
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Feb 8, 2006
#2
  • Feb 8, 2006
  • #2
I asked this same question awhile back, I wanted basically what you did. From what I recollect a "decent" driver around town would be using 3.50's. The five speeds low first will basically compensate.
 
S

steel1212

Active Member
Jun 24, 2004
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Frankfort, Ky
Feb 8, 2006
#3
  • Feb 8, 2006
  • #3
hehe I have 4.11s and I don't mind them but if I try to go much over 75 or so I'm pushing the 3k mark on my tach. I'm probably going to be dropping to 3.70s sometime in the future.

Use this http://www.ringpinion.com/content/calculators/RPM.asp
 
6

66moneypit

Member
Dec 28, 2004
536
0
17
Northern Va
Feb 8, 2006
#4
  • Feb 8, 2006
  • #4
http://www.stanginfo.com/Gears/GearOptions_view.php

Should help you a little,
 

12sec67

Active Member
Oct 6, 2003
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San Diego, Ca
Feb 9, 2006
#5
  • Feb 9, 2006
  • #5
if you go to the 5.0 tech/talk everyone mentions the 3.73's or 3.70's for a 9" as a DD or a cruiser with the 5 speed.

i would of gone to 3.70's or 3.80's with my AOD but i take my car mostly to the track so i went to 4.11's.
 

LMan

Founding Member
Aug 10, 2002
1,246
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Mom's basement
Feb 9, 2006
#6
  • Feb 9, 2006
  • #6
12sec67 said:
or 7.70's for a 9"
Click to expand...


 
D

D.Hearne

New Member
Sep 29, 2000
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south louisiana
Feb 9, 2006
#7
  • Feb 9, 2006
  • #7
Go with 3.50's or 3.25's. With the what(?), 3.35 1st in a T-5 , you'll tach out 1st before you're ready to shift in the "heat of battle" with 3.73's or 4.11's. With those low gears, it'll be almost like having a granny gear 1st in a pickup. Good for starting heavy loads on a steep grade, but nearly useless for everyday driving. You'll find yourself skipping 1st in most take offs.
 
S

steel1212

Active Member
Jun 24, 2004
1,180
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36
Frankfort, Ky
Feb 9, 2006
#8
  • Feb 9, 2006
  • #8
If he has the z series the first gear is 2.95.
 
6

68restoman

New Member
Jun 5, 2003
69
0
0
Feb 9, 2006
#9
  • Feb 9, 2006
  • #9
I've been running 3.50's in my '68 with a stock '93 5.0 EFI and T5 for the last year or so both on the street and at the track. It's not bad, especially with all the low end torque that the EFI gives me. However, I think 3.70's would be better at the track and make overdrive more useful on the highway. I'm having my diff. rebuilt with a Truetrac as we speak and am going to 3.70's while I'm at it....

68Restoman

 

rbohm

Founding Member
Apr 12, 2002
6,698
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204
tucson,az
Feb 9, 2006
#10
  • Feb 9, 2006
  • #10
since you are running a T5, then i recommend no more than a 3.50 rear gear. more than that and you are shifting for second almost as you let out the clutch. i also recommend that you run at least a 25" tall tire as well for the same reason. the other thing is that you really dont need alot of rear gear in the early cars as they are fairly light.

for those who run an AOD, i recommend that you run a 3.73-4.11 gear on the street. that will compensate for the high 2.46 first gear in the AOD.
 
I

Irish_AL06

New Member
Feb 8, 2006
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Feb 9, 2006
#11
  • Feb 9, 2006
  • #11
I bought it with a 3.50 in it so it looks like ill give those a whirl for now....Thanks for the help
 

latamud

Founding Member
Oct 22, 2002
791
2
19
Tampa, FL
Feb 9, 2006
#12
  • Feb 9, 2006
  • #12
I just swapped 3.50 for 3.73s in a 66 w/351w and T-5. Its a different car. The 3.50s will be way more streetable for daily driving and be plenty for country roads. I miss the gas mileage but I want to opentrack my car so who cares now? I also am running a 9" w/4.11s in my Barracuda with a Ford T-5. It is fun to drive, but not long distance.
 
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