Ford 8.8" Ratio Swapping?

[AL427SBF]

Just how much of an ordeal is it to change out your rearend ratios on a Ford 8.8"? I'm starting with a 3.27, but may decide a 3.31 would be better, or even a 3.08?

[Dwight]

what is your tire size?
does your motor make a lot of low rpm torque? what motor will you use?
what trannie will you use? overdrive 5 speed?
is your Cobra a street car or race car?
if street, will you cruise at 70 - 80 a lot?

standard 8.8 gears are 3:08, 3:27, 3:55, 3:73

I have 25 1/4" tires, TKO600 .64, stroked small block, lots of low end torque. I can cruise 70 mph at 2000 rpms.

you need to pick rear gears to match your driving.
Dwight

[fordracing65]

Don't fear the gear, go 373 or 410, you will love it, its a cobra

[joyridin']

You wouldn't want to mess with a 3.31. It wouldn't make any difference. Even a 3.08 from a 3.27 will not make a huge difference.

Do the calculations:

Automotive Converters and Calculators

[mpanten]

Originally Posted by fordracing65

Don't fear the gear, go 373 or 410, you will love it, its a cobra

Yep, went from a 3.27 to a 3.73 and like it. if you have never done a swap have someone do it. It's not that hard but there are quite a few things you can screw up if you dont know what you are doing,

[AL427SBF]

"if you have never done a swap have someone do it. It's not that hard but there are quite a few things you can screw up if you dont know what you are doing"

That would be an answer to the question, thanks mpanten.

[mpanten]

No problem, price wise you should be looking at 550-650 dollars parts and labor included.

[the_tool_man]

Originally Posted by AL427SBF

Just how much of an ordeal is it to change out your rearend ratios on a Ford 8.8"? I'm starting with a 3.27, but may decide a 3.31 would be better, or even a 3.08?

[EDIT] I didn't realize I was responding to a 3-year-old thread. Info still pertains, however.

I've done a couple of 8.8's (in Mustangs). It's not that hard to do. For your first one, I'd recommend you get someone with experience to help, or at least supervise. The main thing you want to make sure of is that the backlash and gear pattern are within spec. Otherwise, they'll be noisy. It's a little fiddly, and may require you to take it apart and put it back together a few times. But it isn't too difficult. Where people go wrong is getting impatient, and just getting things "close enough", to avoid another round of adjustment.

The best thing you can do to make it easier is to get FMS gears. I say this because they jig them to have a consistent pinion depth when they are lapped. Otherwise, you may have to disassemble a few times to get the pinion depth right. Do not, under any circumstances, buy Richmond gears, unless you like gear noise. I have no experience with other brands.

One last thing. A weak link on an 8.8 is the factory crush sleeve. They can creep, and allow the pinion seal to fail. Replace that with a solid spacer and shims.

Regards,
John.

[Rick Parker]

One last thing. A weak link on an 8.8 is the factory crush sleeve. They can creep, and allow the pinion seal to fail. Replace that with a solid spacer and shims.

Good point on Ford 9 inch too.