Drivetrain Swapping A 8.8 Into A 79

Discussion in 'Fox 5.0 Mustang Tech' started by GoldenEagle91, Mar 17, 2014.

  1. Hi guys,

    I recently found a 8.8 rear end out of an auto stang that the owner says has 3.27 gears (stock) out back. I plan on swapping this into my car prior to putting in my rebuilt motor because I don't believe that the stock 7.5 will stand up to the output of my new setup. In order to install this correctly I was wondering if the parts that I have links to will be all that I need to pick up.

    Rear end installation kit:

    Differential Rebuild w/ carbon discs:

    As a side note it says I'll need a S-Spring for the 28 spline axles but I would imagine that there should be one in there. Whether or not that will need to be replaced I am not sure but if you have any opinion or input feel free to drop it here.

    Speedo gear:

    Gear Oil:

    Another side note: On the gear oil I assumed that because this will be a daily driver that having a higher viscosity would be better to deal with heat but I may be mistaken. If there is a better route to take give me a heads up.

    Thanks guys,
  2. The rear should be a bolt in. Run whatever Ford calls for fluid viscosity. It is what they want for a daily driver. Use the friction modifier additive.
  3. You don't think it's worth it to pull out the diff and rebuild it prior to putting it in? And it is necessary to add the friction modifier although the royal purple says they already have it in there?
  4. If you think it needs serviced, by all means do it now. If I was tearing into it, the rest of the bearings and seals would be new too. I bet the S spring should be OK, but there are others with more experience with rebuilding tight rear ends. And yes, I would add the modifier anyway. It is cheap compared to tearing it apart again for chattering clutches. And if you are using Purple stuff, I bet you want it done right the first time.
    GoldenEagle91 likes this.
  5. That is exactly the information I was looking for. Thanks man