9" vs 8"

[blackx 10]

Ok trying to find the differences betweent the 9" and 8" rear ends in the 69 stang. I want a 9" but the two 3rd look almost exactly the same. What might differntiate between the two.

 

This might be some good info too.

 

I was told I have an 8" 3rd but the bearing when I changed the pinion bearings all match up to a 7.5 or 7.25 rear. Was doing some looking around and all the 7" rears I find are not 3rds. Can somebody help me out here.

 

Also if this is possible. Can i take a 3rd from a true 9" and stick it in the 8" housing. Bolts look the same to me right now but i can be wrong. Trying to get some more traction in the rear on the strip and not wanting to waste a bunch of money on some other axle i don't really want.

[bswor 76]

http://www.kevinstang.com/Ninecase.htm

[blackx 10]

thanks that is alot if info..

[69mach1t5 104]

thx bswor i was looking for that link , I use to have it bookmarked but lost it !!:online2long:

[blackx 10]

Just another dumb question after reading all of that. Even though the bolt patterns are the same from the 8" to the 9" you would not be able to put a 9" setup in an 8" rearend right???? Because of the depth that is needed for the ring gear..

[69mach1t5 104]

No you could not.

[blackx 10]

No you could not.

 

Thanks now I know what I need to be looking for....

[bnickel 10,004]

if yours has a removable carrier that bolt up to the engine side of the diff you have an 8" or 9" rear. the 8" would have come with the 250 six banger and the 302 v8 all other larger motors, 351 2v and up, would have the 9"

 

if your's has a removable inspection plate on the back side of the diff it would be the 7.25" rear. if your car originally came with a v8 you've got an 8" at minimum and maybe a 9"

 

if your car had a 200 ci six cylinder originally then you'll have the crappy 7.25 rear.

 

good luck and i hope you don't have the 7.25"er

[blackx 10]

if yours has a removable carrier that bolt up to the engine side of the diff you have an 8" or 9" rear. the 8" would have come with the 250 six banger and the 302 v8 all other larger motors, 351 2v and up, would have the 9"

 

if your's has a removable inspection plate on the back side of the diff it would be the 7.25" rear. if your car originally came with a v8 you've got an 8" at minimum and maybe a 9"

 

if your car had a 200 ci six cylinder originally then you'll have the crappy 7.25 rear.

 

good luck and i hope you don't have the 7.25"er

 

The car came originally with a 289. No rear cover. It has the removable third and with the above page I found out it is a 8" but what is weird is that when I went to go get new pinion bearings they all matched up to a 7.25. That is what is confusing me.

 

Would an 8" be a decent axle to build up for drag racing or should I try to keep my eyes open for a 9" and not even bother messing with the 8"

[bswor 76]

You cant go wrong with a 9", dont even bother with anything else! :)