I have 2.25 ratio in the 9"third member, anyone know where I can get a good used one? with a ratio around 3.00 -3.23

 

Are you sure thats your current ratio? Ive never heard of a gear that tall. Anyway, i have a good used set of 3.00 gear out of a 9 inch here in NC. Let me know if youre interested.

 

yes its 2.25. I have the FORD MANUALS that were for all models during 77'. I have matched my door jamb codes to the book over and over (just in case) the truck came with the tow package (thats what the window sticker says) what gear ratio should i use???? thanx for the help, i hope you get this

 

Sean, unless there was a screw up, the 2.25 would not have been used with a tow package, more likely a 3.75. A 2.25 is an econo gear.


John

66 F100s
In the still cool hours of the night, you can hear chevys rusting away.

 

those were my thoughts exactly........ The tow package consists of the 400, C6, HD radiator,and 9"rear end......as far as the gearing goes, did they have optional ratios inside the C6 to give the final drive ratio a tweaking?? I mean , if that were so, they could use 2.25 gears in the 9" but lower ratio in the c6,
I have checked and double checked my manuals, they are 2.25, the tallest gear on the list(of about 50 different codes)
Im lost

 

Sean, You seem a little confused. The output on a C6 is 1 to 1. All Ford 2wd 1/2 tons have 9" rears. The gear ratios can run from 2.25 to about 4.11, maybe a little shorter. From what I have picked up on (hands on)with mid 60 to 70 trucks, an average would look like this. V8 sd 3.25, V8 auto 3.00, I6 sd 3.75. The 2.75 was mostly a car gear, used in some later trucks for higher mpg. Any towing package will have a higher number rear gear for better pulling, and less mpg.

A 1 to 1 output into a 2.75 means the tires are rolling fast, with a 3.75 the tires are slower. To run 60mph, the engine turns more rpm with a 3.75 than a 2.75.

Hope this helps. :-)

John

66 F100s
In the still cool hours of the night, you can hear chevys rusting away.

 

 

you learn something eveyday!! :O) so, what about those 3.00 gears?? could i slip them into the third member I have?? im an inexperienced drivetrain builder.... thanks for the input...

how much you want for the gears??