[graygator]

Rear toe.
How can it go straight with the rear toe like that.
I recommend you keep it simple, find a long straight edge and put it against each rear tire. Trace the outline on the garage floor on each side.
These cars are old and some have lived hard lives. Assume nothing is straight.
But keep it simple, and maybe try just letting someone else drive it while you follow it. You might be surprised how it tracks.

[Joe-Touring]

First two shops are essentially saying the same thing in different ways. The thrust angle is the angle of the rear axle vs the car’s centerline. Rear toe is the individual measurement of each tire.

Since you have adjustable rear arms, get a four wheel alignment. Rear toe should be as close to zeros as possible.

Make sure to tell the shop that you want as close as possible to the UMI recommended specs.

[gtorich]

Joe, thanks again................trying to get this straight in my stupid head............on my upper adjustable arms i used that for pinion angle............i thought the lower arms only went forward and backward.................so with the arms i should be trying to get 0.00 on left toe and right toe. In a perfect world you want the thrust angle to also be 0.00

Does having bigger tires in back have any effect on this deal..............the fronts are P235/60/15....................rears are P255/60/15

Im hoping this all turns out well...........................as far as the umi specs im just gonna do the street one.................i have no idea what performance street means............lol, im taking my corners at maybe 10mph.............Rich

[Jimbobeast]

Where do I find optimal alignment specs for a stock 1970 GTO convertible? I have a friend who can give me any specs I desire.

[Joe-Touring]

Originally Posted by Jimbobeast

Where do I find optimal alignment specs for a stock 1970 GTO convertible? I have a friend who can give me any specs I desire.

Do you still have factory control arms? The stock stuff limits what you can do.

The simplest way to put it: tell him to max out caster while giving you some negative camber, and slight toe in.