What Size Mudders for My 68 GTO Convertible 4x4?
 

So I yanked the tired stock springs on my 68 and installed some stiffer Umi springs front and rear. Supposed to be "stock height." But that doesn't look like stock height to me.

I can remove the front coils and trim them to drop the front a bit; currently it's sitting a tad higher than the rear, so I definitely want to do this.

The problem is the back -- it looks pretty high here. And the springs have a pigtail top and bottom, so you can't trim them. Think I need to return them and ask for the springs with a 1" or 2" drop.

Car is a cruiser, but I would like it to handle reasonably well. Also has tubular control arms front and rear with Bilstein's all around.

Or I could leave it as-is, install some Buckshot Mudders, and go hit the mud...

Thanks,

Scott

After spring swap:
http://i102.photobucket.com/albums/m...psdylqhnih.jpg

Before spring swap:
http://i102.photobucket.com/albums/m...pslufnxevv.jpg

...do the fronts first.

My 68 had a similar high stance 12 years ago. The front has settled down some but not to the goal. If i had a care, id redo the fronts first.

I was kind of hoping you'd recommend that I go with the mudders...

Looks like I can get 1" and 2" lowering springs from UMI. I'll have to do a bit of measuring to see what would work better.

A factory body manual would have the curb heights at the rockers for a new car. I believe they were a little higher in the front than rear right out of the box. Not sure why the factory did that.

Those do look pretty high all around though. Have you driven it much? Springs will settle a little bit.

Or just put the mudders on it and go have some fun!

If the springs are not indexed properly in the lower control arms pockets you can get that "look"

Have you checked that out when you installed the springs?

Tom V.

In '69 it was 9.1" at the rear and 9.6" at the front. As you note, it's higher in the front than the rear. I need to measure where I'm at now.

Haven't driven it with the new springs yet.

Thanks

They are properly indexed, with the tail of the spring fitting in the notch.

Thanks

It looks pretty even to me, just way too high.
 

Looks like about 3" too high all around by looking at the pics.

And, as mentioned by Will, it will settle some when you 'break in' the springs by driving it around. But normally only about 1" or so. :drive:

You're probably going to need to cut off about 1 full coil in the front and then get shorter rear springs to get it down where it needs to be.

Or you could cut down the front springs and fill the trunk with about thirty cases of root-beer. :rolleyes:

Good luck!

Remember that cutting springs increases the stiffness of the remaining coil. If that matters to you.

Sam

Back in high school when we used to cut springs with a grinder, we’d make people drive ‘em for a few days before we cut more - they’d tend to “settle.” I’m pretty sure that the new “drop springs” did that too.

Edit - I just saw that Joe mentioned that, too. You’ll still want to let them settle before you start cutting.

For 1968 GTO´s you can use TRW/MOOG OEM replacement springs 5386 in front and 5401 (regular) or CC501 (cargo coil) in rear.

Mudders are optional.

You didn't mention if you have the a arms off or not but they should be tightened up with all the weight on them. If it is on jackstands when you tighten everything up you will get that look

Thanks for the input. Will try to put some miles on it soon to see if things settle a bit.

Yep. I'm familiar with how that works. I'm hoping for a firm ride; was way too loosey goosey before the spring swap.

Thanks for the input. Real world experience is always helpful.

Thanks, Kenth. I appreciate the input.

Scott

Yep. Familiar with how that works as well. Control arm bolts are all loose, front and rear.

Thanks for the input.

Scott

I put Cargo Coils on a '67 Lemans convertible and a '87 Cutlass Supreme. In both cases I thought the ride quality and the ride height was perfect.

Winner, Winner, Chicken Dinner! You were pretty close.

The factory spec is 9.6" at the front (bottom of rocker to ground) and 9.1" in the rear.

I did a quick measurement and came up with 12" in the front (2.5" too high) and 11.5" in the rear (also 2.5" too high).

Figure I'll need to slice some in the front and replace the rear springs.

Thanks

Scott

IIRC .50" of coil cut results in 1" of drop.

I had to pull mine out and trim them up. Keep in mind that they will settle eventually. I trimmed my coils to provide an additional 1" of drop, but after a year of cruising I'm sitting at 2" of drop overall.