Cut From the Bottom. Springs on chev trucks have a bottom, they index and slide into a notch on the LCA
apparently it doesn't matter where you cut from? ive always cut with the top. you can tell the top from the bottom cause the bottom kind of flattens out and the top stays round through out the whole spring. like Brandon said, the lower kind of twist into a notch into the LCA compared to the top just kind of sits in that rubber boot which is why I always cut from the top. so it ddidnt mess with the way the spring sat in the LCA pocket. use a cut off wheel to keep heat low and not fuck up the spring rate.
Buddy of mine cut his springs on both of his STi's, shittiest ride I've ever experienced. Fucked his spring rate on all 4 corners, that's why I said you don't cut springs.
My first lowered truck had springs cut for 4" drop until I could afford spindles. Not bad at all beside camber. I also cut from the top
He probably put too much heat on them when cutting which will fuck them up..cut with a cutting wheel and keep heat low like ryan was saying and you cant even a difference in ride
your comparing apples to oranges. an sti is set up with a macpherson strut suspension set up, where a truck has short arm long arm suspension set up. then you got possible linear vs progressive springs which im sure the sti has a linear spring. but still, there are a bunch of variables when cutting springs. my audi has a strut up front and a spring in between a control arm and the body in the back. the rear is progressive so I wouldn't cut it since the shorter it gets the stiffer it gets. its just cut springs have been proven to work with trucks.