[Pershing]

Can anyone tell me the original front suspension alignment specs for a 1967 GTO? Also, any modifications for radial tires. I have Coker red line Firestone Wide Ovals which are radials. Thanks

[Stuart]

This is from an old Motors repair manual:
Caster: limits, -1 to -2 degrees, desired value -1.5 degrees
Camber: limits, -.25 to +.75 degrees, desired value +.25 degrees
Toein: 0 to 1/8 inch
Those are the original values, I don't know what if any changes should be made for radial tires.

[OG68]

There seems to be a general consensus to have as much Caster as possible within the limits of your factory arms.
Other factors are manual or power steering. Additional Caster often equates to increase steering effort as well as high speed stability

This is what I have picked up along the way.

With the factory arms and radials

Caster: +3-4* or as much as you can get dialed in.
Add .5* to passenger side if majority of driving is on crowned roads
Camber: -.125* to .250*
Toe: 1/8"

[Pershing]

Thanks to both of you. I can imagine that the original specs would have to consider that most cars had manual steering. So trying to make the steering easier would lead them to specify negative caster and positive camber for the optimum setting. Not sure what radial tires did to the settings when they adopted them as standard in the 1970's. Anyone else have any advise?

[GT182]

OG68, is yours with power steering? My 66 GTO is manual steering with the factory arms and I've been looking to have it aligned, but have never found any newer info for doing it with radial tires these days. The only difference is that I now have disc brakes up front on the drum spindles.... A Scarebird upgrade that works very well. With 225/60-15 BFGs on Cragar rims.

[OG68]

I used those settings on my El Camino with PS and UMI upper control arms but added another degree of Caster (5*). Factory gearbox upgraded by LEE Steering to 12:1 ratio and 35# torsion bar. Car handled very well almost on par with the wife's SRX.
The GTO is still in restoration. I added .5" taller upper ball joints to the factory control arms and a 1.125 front/.875 rear sway bars. Not looking to race around the corners with this one. Just a better footprint.
Originally manual steering with factory radial tire option, but I'm adding a 69 GP variable ratio box rebuilt by LEE with an increased torsion bar setting.
There wasn't a different factory alignment setting that I was aware of for the radials.

[tempest1964]

OG68, when you installed the UMI uppers on your El Camino, did it change your wheels in your wheel well? In other words, did you have less clearance between the wheels and wheel wells? Seems like I read on the forum doing the uppers only re-centers your wheels a bit. I have actually contemplated UMI uppers and .5” taller ball joints for my ‘64.
Thanks

[Pershing]

Originally Posted by Stuart

This is from an old Motors repair manual:
Caster: limits, -1 to -2 degrees, desired value -1.5 degrees
Camber: limits, -.25 to +.75 degrees, desired value +.25 degrees
Toein: 0 to 1/8 inch
Those are the original values, I don't know what if any changes should be made for radial tires.

So I did find a shop that had shims and knew how to use them. We tried for a more modern radial PS setup with positive caster instead of negative, and more negative camber. Toe-in was no problem at the limit of 1/8". Camber was set at the limit of -1/4*. Caster was the problem. They were serious about the limit being -1* as the closest you could get to positive. Trying to get to +2 resulted in about an inch of shims. So we backed it off to the limit of -1*. So that's the story from here and I post this as help for anyone else. Unless you change the factory components, the best you can do is to stay within the limit ranges.

[OG68]

Originally Posted by tempest1964

OG68, when you installed the UMI uppers on your El Camino, did it change your wheels in your wheel well? In other words, did you have less clearance between the wheels and wheel wells? Seems like I read on the forum doing the uppers only re-centers your wheels a bit. I have actually contemplated UMI uppers and .5” taller ball joints for my ‘64.
Thanks

I didn't notice any difference. 1" lowered springs. Tires were 245/60 x 15 with plenty of room.