I have a stock 71 f100 4x4.It has 3.50 gears .I put 33" tires on it and now I have problems climbing hills and pulling my camp trailer up hills. I was told to change my ring and pinion. If I change it what gears should I use? I rarely drive it on the hiway.It rarely sees speeds over 55-60.Mainly I drive it on back roads in town and I take it fishing or pull my trailer to go camping up steep grades in mountains.Can anyone suggest a good gear ratio for my truck? Thanks

 

Try this site, www.4x4cyberstore.com, They have a tire/gear ratio chart, it will allow you to choose the best RPM/MPH for the use of your truck.

 

I looked all over their site and can't find the chart. Can you paste the web address of the chart page?

 

Sounds like you do not have a big block (360/390) and assuming you have a 302 and automatic I would say go with the 4.56 gears if it does not see much highway time.

Using http://www.4lo.com/

31 inch tire (what a 33 really measures), 1:1 transmission, 1:1 transfer case, and 4.56 gears you would be pulling 2700 rpms at 55 mph.

 

I have a 390 I just replaced the 360 that was in it.The FE 's are the best in my book.

 

Sorry, they seem to have deleted that chart, since I visited last. Here is a valid link to another chart,http://www.sierrabronco.com/TireGearRatio.htm.
I should have checked the other one before posting.

 

3:73 rear end gears!

 

4.10 seam to work good