Vintage Mustang Forums banner

1965 Factory GT Mustang Rear end

8K views 20 replies 8 participants last post by  supershifter2 
#1 ·
I have a true early 1965 factory GT fastback that has a 9 inch rear end in it. Only info I find is that Hi-po cars had 9 inch rear ends but wanting to know if GT's could have a 9 inch from the factory or were they all 8 inch? Thanks
 
#2 ·
All '65 V8s were all 8" unless they had a K-code motor, GT or not. But lots have been swapped out over the years. I did it myself, to my '66 GT fastback, many years ago (since then I have switched back to the original 8" housing). If you have a true early Mustang 9" rear (with the narrow axle tubes), a K-code guy might be willing to pay a lot for it.

How "early" is your car?

MrFreeze
 
#7 ·
Yeah, I'd like to see photos of said 9" rear axle as well.
Probably done long after the car was built. I'd find
it hard to believe the assy line would slip a 9" in if they
were out of 8's. I've seen lots of slow ratio steering boxes
where they didn't belong and a few ft sway bars over the
years though.

ex-Global West GM
1991-1995
 
  • Like
Reactions: PaulsPizzas
#11 ·
If the tubes are straight then it's an 8 inch. Tapered tubes (i.e.. tubes leave the diff as one diameter, then partway out "step down" down a smaller diameter before they reach the brake backing plates) indicate a 9 inch.
 
#16 · (Edited)
Um, er, not so fast.

ALL 65-66 Mustang rear axle tubes were stepped-down at the springs, 7", 8", and 9". ALL 67-73 Mustang axle tubes were straight.

There are no "casting numbers" on the housing. The cast carrier, of course, does have numbers. However, this is a 9"-



It's just not a 65-66 Mustang axle.

The rubber pinion bumper on your car is mounted on the floor of the car. The steel plate is the floor-mount type, i.e., your car left the factory with an 8" axle.
 
#12 ·
What I see in Pictures;
1. the bulge of a 9" gear in the rear of the center section.
2. what appears to be a C7AW-E 9" center with the fill plug on the side, a C7AW-O pinion snubber,
and a floor mounted GT snubber plate and bump.
3. the gradual step down of the axle tube as seen on a 9" axle housing.

If you wanted to get some casting numbers off the housing, the pinion snubber and a picture of the axle ends, at the brake drum, you would know for sure. Brian
 
#17 ·
Well I am easily confused but doubtful that a 65 GT ever came with a 9" axle assembly unless it was also a ' K ' code car. In this case it appears to be a 1967 9" axle housing in your 65 GT. The date castings are, on the center case, right/passenger side, on the pinion at the outer forward rim and the axle ends may have a C7AE casting. Brian
 
#21 ·
No 9" in a GT, BUT ! BUT ! I put 9" rears in all my 65-66 GT's in the 70's and 80's. I know other guys that bought the 65-66 9" housings or 57-59 ford housings and put them under their C and A code mustangs. I used 57-59 ford rears and 67-70 housings that I narrowed 1" on each side. I sold the rear out of my 65 K because i never liked the 65-66 necked down housing.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top