I'm only speculating here but I would think the effects of the Guldstand mod would be more evident with a lowed car. Such is the case with using the Hotchkis springs.

If I remember this all correctly the tire goes into positive camber (top of tire leans out/bottom leans in) when compressed. This is bad for cornering and hard nose down stopping. The Guldstrand mod did two things. The A-arm pivot point is moved down and back providing more positive caster and allowing negative camber (top of tire leans in/bottom lean out) keeping the tire surface flat on the ground for hard cornering. Keep in mind the tire will want to roll under during hard corning too.

This mod is much easier to do if the motor is out. I had most of mine together when I did this. I got metal shavings everywhere and made a huge mess. I also had to cut the top of one of the perches for the A arm to clear, and modify one of the back shims to fit by cutting it at an angle.

I put back the factory rubber flaps on the inner fenderwells so you really cant see the leftover holes. And like I said above If I had to do it all over again I may have went with the SPC adjustable arm and tall ball joint. But for the cost of $10 for the Guldstrand book and a couple of drill bits you can't beat the price.