I want to find a higher ratio third member to put in my 9" Ford rear in my 59 F-100.I'd like to do this as cheaply as possible(ie. salvage yard parts). My RPM's on my 6 cylinder are sky high on the highway!
Will third members from any year and model cars/trucks fit my rear? Is this the cheapest way to go? Anyone know which years and models will fit?
Thanks for the help!

 

Any year car, truck or van 9" third member will bolt into your housing, but you will have to make sure that it has the same axle spline count (28 or 31) as the axles in your truck. There are a few variations on the pinion yoke, so try to find one that is the same as yours. I would go 3:00 or lower with a six or loads and hills will get you the one finger wave.

L. Edmundson
31 crewcab
35 pick up
72 F-100 lowrider
79 F-150 crewcab (custom built)

 

Is there a way to find out what model cars/trucks have the same number of splines as a 59 F-100 without pulling them out? If there was a list of vehicles with interchangeable third members?
Maybe I am being dumb about this and maybe there is an easier way to address my low gear ratio, but I have visions of pulling several third members only to find out they won't fit my axle splines.

 

this is not actual proof, but from experience. Cars should have 28 splines except for late 60's -early 70's muscle cars with the "drag-pak". Trucks from 57-72 used 28 splines. 73-86 used 31 splines. If rearend has not been tampered with, they should have a tag telling you the gear ratio. The ratio is in the bottom left corner e.g. 3.25. If it has a L in the numbers, it is "locking"

 

>I want to find a higher
>ratio third member to put
>in my 9" Ford rear
>in my 59 F-100.I'd like
>to do this as cheaply
>as possible(ie. salvage yard parts).
>My RPM's on my 6
>cylinder are sky high on
>the highway!
> Will third members from any
>year and model cars/trucks fit
>my rear? Is this the
>cheapest way to go? Anyone
>know which years and models
>will fit?
>Thanks for the help!

I am looking to change out the 9" 3.00:1 for a 3.89:1 or 4.11:1 I would be willing to trade straight accross depends on were you are located. Is is a 28 spline. I am in the So. Calif. Area. let me know. I will be putting in an overdrive trans and want the lower gears.

ke6bnl@juno.com

 

Mine is a 3.73 and I am located in Virginia!

 

I had a 59 and put a third member from a 66 Galaxy (3.00:1) it worked great.I also had to use the axles from the Galaxy they were the same length but slightly smaller dia. and had 31 splines.