1966 Mustang Rear End

I have a mustang with a newly rebuilt 289, and C4 trans, but the rear end is for the six cylinder. Will my four lug rear end stand up to the engine and trans? I also had the rear end rebuilt, can i just replace the axles?

Maybe you can look for a donor car? You could get all the 5 lug stuff from it. Did you do the wrench time? if so then it will not be so costly to get it done.

I would bet that the six cyl. things will hold if you are not out busting balls with this car.
Do remember that you added weight to your car and speed so it will also need more time and strenght to brake.

Go find that donor car for a few hundred bucks get the rear end and the spindles. And it does not have to have disc brakes just cause its a v8

Scott.

Thought that would be the case. Thanks for the information.

You will NOT BREAK your 7.5" rear end unless you dump your clutch from about 5,000 rpm's.


Don't worry about it unless you are racing your car on the strip...

Many of the six powered autos had 2.79 rear axle ratios, to which you will not like. They also had 13 inch rims, which you also may not like.

The axles do not swap, and beware that the U-joint may not also swap.

Is generally easy to locate and obtain a V-8 rear axle as the majority of cars came with such.


Wm.

Originally Posted by FEandGoingBroke

You will NOT BREAK your 7.5" rear end unless you dump your clutch from about 5,000 rpm's.


Don't worry about it unless you are racing your car on the strip...

Wait a minute. FE, are you saying that you can put a 289 into a straight six Mustang car and it will be okay? Perhaps gradually upgrade radiator, suspension braking, etc?

I've been wanting to have an 8 but I can't really afford to do all the other stuff, at least not right now.

Ditch the 6 banger rear axle. An 8 in will be fine for any thing other than Race car. I am installing a 68 8 in in my son's. It is a little wider but we are using 05 Mustang rims which have a bigger off set which should be perfect.

Replace the junk 7.25" diff with a 8" from a v-8 vehicle.
You can then install a different gear ratio & a limited slip-equa-lok or any other limited slip as necesary.
The 8" has the removeable hog head & is the way to fly.
You can then chose your gear ratio of your choice.
I don't know on your 66 but my 67 the driveshaft & u-joints were ok.
The big benefit is 10" brake drums. Bill

I tore two of the four lug rear ends out of my Falcon in a year running a 200" six....
I don't think it will hold up to a 289 for very long!