67fastbackgreen

I guess the axle in my donor car is an 8.8" 4 lug and the one I have my 67 is 8" 5 lug. How can I make this 8.8" a 5 lug so I can put it in my classic?
Thanks!

Starfury

Is your donor a fox body? If so, it's a fairly simple conversion. Here's what you need:

Axles - Driver's side axles from an '83 to '92 4 cylinder or 3.0L V6 Ranger/Bronco II with a 7.5" rear end, or Aerostar passenger side axles from an 86 to 97 model (they should measure 29-5/32").
Drums - Use the brakes off the donor vehicle(s), just make sure they are 9" drums. (The Rangers were offered with 10" drums)

Make sure you replace the bearings on the axles before you install them. Who knows how long the existing ones have been in place.

I suspect you may have to fab up some brake lines, but that's pretty easy as well.

andrewmp6

Is your car now a 8 inch or a 7.5?

NeoTokyo

He said he has an 8" right now.

Great info Starfury.

Starfury

Forgot to add: you'll still need to hack off the 4-link mounts and weld on some leaf spring mounts. Proper pinion angle will need to be taken into consideration when doing this. You'll also need a yoke from a fox body driveshaft, as I believe the 8.8 uses a bolt-on yoke where the 8" uses a pinion yoke that bolts directly to the u-joint. You'll then either need to use a conversion u-joint, or get a whole new driveshaft fabbed up. I'm not sure if the stock one will work length-wise.

67fastbackgreen

Wow, this is great! How do you guys know so much? Thanks for your help, if you can bear it, I'm sure I can use your knowlage later in this build.

Thanks again!!

67fastbackgreen

I did say 8", but that's only because it's definetly not a 9". I didn't even know there was a 7.5...How can I tell??

andrewmp6

The 7.5 was used a long time pretty much any 6 cylinder or 4 cylinder mustang from the 60s tell 04 had one.On the old mustangs the 4 lug inline 6 cars had it and it has a removeable diff cover.The 7.5 and 8.8 look just a like but for the lower bolts on the cover are wider on the 8.8.Honestly i would keep your 8 inch if its not messed up its already in the car and will handle a small block just fine.By the time you break a 8 inch a 9 inch would be needed.

Starfury

Honestly, google I had an 8.8" that I was going to swap into my car, but it's since disappeared (don't ask). The advantage to an 8.8" is that it's stronger than an 8" but not as heavy as a 9". Good for a road racing car where you want to keep weight down, especially unsprung weight.

Andrew does have a point, though. An 8" with a good differential will take quite a beating, and it's much easier to work with in the vehicle than an 8.8". If you're not going to be abusing your drivetrain, you may consider building a 3rd member to swap into the 8". It would definitely be easier.

andrewmp6

The way i look at you can sell the 8.8 use the money to rebuild the 8 inch how you want and have a good strong rear end that already fits and will handle most small blocks in a street car.To me i rather use the 8 inch i know the 8.8 has a bigger ring gear but if you break a axle or c clip you can't limp it home like that.With a 8 inch and 9 inch you can break a axle and still limp it home if the housing isn't messed up.If your planing to have a big power monster i would skip both and go for a 9 inch.