Looking for rear end opinions

[1985olds]

The car is a 1985 cutlass. Turbo 5.3 making about 500-550 whp through a t56 magnum. Carbis used for a daily on nice days and autocross. I have an 8.8 that I can build to make a stout rear with Ford 9 inch ends to eliminate the c-clips and the necessary instant center correction kit for about $1900. The other option is a quick performance bolt in 9 inch for about $2200-2300. I worry about the added weight and parasitic loss of the 9 inch and the rear geometry issues with the 8.8. Looking for opinions on which one you would pick? Thank you.

[CSG]

I have made WAY more than that and used 8.8's. What geometry issues are you referring to? Trying to use the factory tabs and upper mounts?

[1985olds]

I have made WAY more than that and used 8.8's. What geometry issues are you referring to? Trying to use the factory tabs and upper mounts?

Yes, the upper mounts, I'm not worried about the strength aspect of it. I'm just wondering if the hassle to make the 8.8 work is worth the decreased weight, parasitic loss and expense of the 9 inch

[CSG]

For me I would chose proper geometry. I will spend hours in cad fine tuning suspension designs though so I can tend to get too wrapped up in trying to make something "perfect".

[parsonsj]

I'd use the 8.8, and Ford gears. The 9" with aftermarket gears will be noisy -- with a special whine right at cruising speed. :(

[andrewb70]

Does anyone make a 8.8 rear that has the right "ears" for the upper control arms on a A-body?

Andrew

[parsonsj]

I'm sure I can.

[CSG]

What you want is a low profile link between the two ears. That way you can mount a 3 link!

All the 8.8's that i am aware of have the same ears or none like the explorer. I do like the 3 link though if you are interested in going that far. I did that on a fox coupe and it worked well.

[130fe]

I have a Quick performance 9 inch center section in my 68. Whiney gear noise at 40 mph and up. I would use the 8.8 if you are able to fab the pieces to put it in.

John, are factory 3.90 9 inch gears still available?

[CSG]

1985Olds, I received your PM. I decided to reply here so others can join the discussion, always best to get more brains involved.

I see that you have 3 options if you wish to run a 8.8.
(1) modify the housing to re-locate the ears
(2) fab brackets to relocate the ears
(3) use a type of 3-link

If you choose option 1 or 2 then the first thing you have to do is figure out where the ears need to be. This may eliminate one of the options due to physical limitations. For option 2 look into the systems like this: http://www.baselinesuspensions.com/kits/outlaw.htm for ideas.

If you choose option 3 then you have two common choices. A torque Arm or the short upper single arm type. I have ran both and have no complaints about either. For me personally I would consider purchasing a Maximum Motorsports torque arm for a mustang and modifying the crossmember to fit your car. Obviously you would still need something for lateral location so you would need to fab a panhard bar. I say this option for the ease of fabrication and it is a quality piece. The short upper option will require 100% new components, so a lot more work involved. Look at the old EVM 3-link for examples of this type setup.

[SSLOW6.0]

1985Olds, I received your PM. I decided to reply here so others can join the discussion, always best to get more brains involved.

I see that you have 3 options if you wish to run a 8.8.
(1) modify the housing to re-locate the ears
(2) fab brackets to relocate the ears
(3) use a type of 3-link

If you choose option 1 or 2 then the first thing you have to do is figure out where the ears need to be. This may eliminate one of the options due to physical limitations. For option 2 look into the systems like this: http://www.baselinesuspensions.com/kits/outlaw.htm for ideas.

If you choose option 3 then you have two common choices. A torque Arm or the short upper single arm type. I have ran both and have no complaints about either. For me personally I would consider purchasing a Maximum Motorsports torque arm for a mustang and modifying the crossmember to fit your car. Obviously you would still need something for lateral location so you would need to fab a panhard bar. I say this option for the ease of fabrication and it is a quality piece. The short upper option will require 100% new components, so a lot more work involved. Look at the old EVM 3-link for examples of this type setup.

Dont forget the S197 Mustang came with a 3 link setup from the factory. If you're going to go through the trouble of cutting down an 8.8, with ford 9 ends, and custom axles, that may be the way to go. You can add a panhard rod and be good to go. This may be the route I on my 86 Monte SS.

[CSG]

Man, I am slipping. I forgot about those and I even built one!

[CSG]

Another option would be a 4-link built like the Steeda 5-link. Mount the upper arms on the tubes and run a panhard bar. Those system worked really well. Less bin due to less angle in the uppers and would be pretty easy to build.

[parsonsj]

Dont forget the S197 Mustang came with a 3 link setup from the factory. If you're going to go through the trouble of cutting down an 8.8, with ford 9 ends, and custom axles, that may be the way to go.

That's the best way. Those housings have 3" axle tubes. Cut off the ends, machine off the center casting link, and weld the resulting hole closed. Then put on SET20 ends, new Ford gears, the diff of your choice, and 31 spline axles. I've found that setup to work really well with DSE's Q-link. Adding brackets for a GM angled 4 link should work really well too.

[parsonsj]

John, are factory 3.90 9 inch gears still available?

Sorry Chris, Ford hasn't made new 9" stuff for a very long time.

[130fe]

That’s what I figured John lol

[1985olds]

Thanks guys for all of the responses. Looks like I'm going to put the 8.8 in with the instant center correction kit so the car will be ready for power tour and try a 3 link setup next winter when hopefully I have time to mess with it. Merry Christmas to everyone as well.

[1985olds]

So I've been collecting 8.8 parts and looks like it's going to cost about the same as the 9 inch. Is the general consensus still in favor of 8.8?

[parsonsj]

That's what I'd do. I know we have testimony of Ernie from Texas being able to make a 9" quiet, but every Tom, Dick, and Harry can do that with an 8.8 using Ford ring and pinions.

[1985olds]

That's what I'd do. I know we have testimony of Ernie from Texas being able to make a 9" quiet, but every Tom, Dick, and Harry can do that with an 8.8 using Ford ring and pinions.

Thank you. Have you ever done an 8.8 in a g body?