Ford 9" vs 8.8"

Kdubslugga

Active Member
Jun 7, 2003
1,515
3
38
Akron, OH
Why are Ford 9" so popular in the Chevy and Mopar world? I would think a nicely built 8.8 with girdle and some 31 spline axles would be just as strong and a helluva lot cheaper. I dunno maybe im wrong, is there any real reason to run a 9" unless you have a 7 second dedicated drag car?
 
Just like the SBC, at one point the Ford 9" was plentiful and cheap. The aftermarket recognized it's durability and versatility, and so started developing modifications for different applications.

By the time the 8.8 came around, the 9" was already king of the mountain. That's just how it works sometimes.
 
To change the gear ratios in a 9" rear axle, you remove the axles and then the entire center section of the differential assembly unbolts from the front. If you have several different gear ratios all built up in different center sections, you can change the gearing in 30 minute or less. It's a great option for dirt track and road race cars.

9in2.webp


For those of you who would like to know more, see http://www.kevinstang.com/Ninecase.htm
 
i went from a 8.8 with 35 spline axles to a 9 inch with 40 spline axles,pro gears, a back brace,35 spile input shaft just because i was doing a big motor with a big turbo and i was being told the 8.8 with that size axles had problems so that y i went with a 9 inch. i was told the spools break because there is not alot of metal at the spool. i was going to be making alot of hp
 
They showed this weekend on extreme 4x4 why the 9 inch was stronger and desired, 1 of the reasons was the ease of gear swaps like jrichker pointed out, the reason it was stronger was the pinion(I think thats what its called) shaft has a bearing at the end after the small gear and it keeps it from lifting under a load.
 
the 9" housings they use in the fast drag cars arent the 9inches you guys run on the street anyway. they are fabricated sheet metal housings and is a metric ****ton lighter those old stamped 9" and cast iron 8.8's