Rear End Gear Ratio - Page 2 - Ford Truck Enthusiasts Forums

Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck

Rear End Gear Ratio

 
  #16  
Old 02-03-2012, 05:02 PM
iMetal
iMetal is offline
Freshman User
Thread Starter
Join Date: Oct 2011
Posts: 41
iMetal is starting off with a positive reputation.
Thanks for all the input. What would be a good starting point on the motor since you think that is where my problem lies?
 
  #17  
Old 02-03-2012, 05:23 PM
Bullitt390's Avatar
Bullitt390
Bullitt390 is online now
Certified Thread Hijacker
Join Date: Aug 2001
Posts: 14,095
Bullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant futureBullitt390 has a brilliant future
I would shoot for 8-12 degree BTDC initial timing and verify the centrifugal and vacuum advance are functioning.

Josh
 
  #18  
Old 02-04-2012, 01:19 PM
restoringmy46's Avatar
restoringmy46
restoringmy46 is offline
Elder User
Join Date: Nov 2004
Location: Ashland, KY
Posts: 873
restoringmy46 is starting off with a positive reputation.
X2 on the timing. Let us know what you find out on you timing. It could be 180 degrees out. Does it turn over good when you start it, hot and cold.
 
  #19  
Old 04-13-2018, 12:59 PM
EmilioJose1
EmilioJose1 is offline
New User
Join Date: Apr 2018
Location: Antofagasta, Chile
Posts: 2
EmilioJose1 is starting off with a positive reputation.
Hello friends, I want to know what differential incorporates my 1975 f100, by the VIN code is a differential with relation of 3.50: 1, and I would like to obtain a relation as much as possible of 2.75: 1 or 3: 1. I would also like to know what model of differential it is, if it is a 9 "ford or it is a Dana or some other, I await your answers, greetings.
 
  #20  
Old 04-13-2018, 01:09 PM
JessyJ's Avatar
JessyJ
JessyJ is offline
Senior User
Join Date: Oct 2017
Location: british columbia, canada
Posts: 280
JessyJ is starting off with a positive reputation.
That pics too small for me to read.Doe,s the rear diff have a cover on it.with bolts.
 
  #21  
Old 04-13-2018, 02:18 PM
NumberDummy's Avatar
NumberDummy
NumberDummy is online now
Ford Parts Specialist
Join Date: Nov 2006
Location: Simi Valley, CA
Posts: 80,737
NumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputationNumberDummy has a superb reputation
Originally Posted by EmilioJose1 View Post
Hello friends, I want to know what differential incorporates my 1975 f100, by the VIN code is a differential with relation of 3.50: 1, and I would like to obtain a relation as much as possible of 2.75: 1 or 3: 1.

I would also like to know what model of differential it is. FORD 9" I await your answers,greetings.
F10 = F100 2WD Pickup

B = 300 1V I-6

E = Mahwah NJ Assembly Plant

V41118 = 1975.

117" Wheelbase.

P = Not listed in paint section of truck parts catalog.

F100 2WD Pickup, 4,650 lbs. GVWR

D 4: D = Black Vinyl // 4 = Styleside Pickup.

C = Ford type 3.03 3 Speed Manual all Syncromesh Transmission.

08 = Ford 9" Rear Axle / 3.50-1 / 3,300 lbs. Axle Capacity.

4,650 lbs. Gross Vehicle Weight Rating.

1975.

91 = Export.
 
  #22  
Old 04-13-2018, 02:40 PM
gittinwidit
gittinwidit is offline
Elder User
Join Date: Mar 2003
Location: Durham, NC
Posts: 724
gittinwidit is starting off with a positive reputation.
I DD a truck with a 302 and C6 that originally had a 3.50 rear gear running 235/75/r15's. I swapped it out for a 2.75 to see what it would do and it lost a lot of power AND lost 4 mpg. But it does 70-80 and doesn't scream like the 3.50, whereas the 3.50 would wind plum out around 70 and it was all I could do to keep up with traffic in the slow lane. My commute to and from work is about all interstate so I decided to leave it 2.75 and I can run the fast lane and shave a few minutes off my commute. So a lot depends on what speed you need it to go regularly.

I've heard the consensus was that 3.25 was the ideal gear to run with this setup for mpg and cruise speed. But I personally have never ran that gear.
 
  #23  
Old 04-13-2018, 05:16 PM
BeauF0RD's Avatar
BeauF0RD
BeauF0RD is online now
Elder User
Join Date: Jun 2015
Location: York Pa.
Posts: 569
BeauF0RD is starting off with a positive reputation.
I have a 1976 F-100 2 wheel drive with a 302, Holley 600 cfm 4 barrel carb., 3.03 3 speed trans., and 3.25 rear gears in a Ford 9 inch, 28 inch diameter tires and my truck is also a dog down low. I'm going to change to a 3.73 posi. center and see what that does for performance . I will not be driving on any freeways, if I were I'd probably go with a 3.50.
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Cdn4X4
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
8
10-04-2016 01:48 PM
LGS
1997-2006 Expedition & Navigator
2
09-24-2016 09:08 AM
rick0516
1961 - 1966 F-100 & Larger F-Series Trucks
7
03-09-2016 08:22 PM
ocala562
1997 - 2003 F150
3
12-03-2011 01:06 PM
Bob's 1984
Clutch, Transmission, Differential, Axle & Transfer Case
2
03-21-2006 11:04 PM


Thread Tools
Search this Thread
Quick Reply: Rear End Gear Ratio


Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.