Hi, getting ready to start assembling the Subframe for my 67 Camaro. Where the upper A Frame mounts I have 2 sets of holes.`' Someplace I found that lowering the mounting points was beneficial. In the past looks like the upper holes were the only ones used. So the question is which ones do I want to use and why.
3 See picture. In the process of removing a Tilt front end and replacing with original sheet metal . Turning into a bigger project than thought it would be.

 

From the factory, our cars only had the upper holes. A previous owner drilled those lower holes on yours, it's what's called the "Guldstrand Mod". You can read about the handling benefits here: How Four Holes and a Bit of Time Can Dramatically Improve Your Car?s Performance in the Turns

 

Does the lower arms have 2 sets of holes?

 

Thanks, looks like they set the camber to zero after modification, but they don't say what the caster is.
Looking at my holes not sure the lower ones were ever used. Can see the bolt knurl marks on upper holes, but no marks in lower holes unless used a non knurled bolt. Guess will try the lower holes and see what happens. The daughter may want to try an autocross or two.

 

No, only one set of holes for lower control arm, 2 sets as pictured for upper .

 

Great info

 

Interesting read, I have not heard of this method before, thanks for the article 69.