I'm no expert either, Kevin, and I'm in the middle of detailing my '68's subframe now. I took a lot of pictures when I disassembled it for I found yellow markings on the underside at the driver's-side spring pocket and on the front frame horn underside. There was also a yellow mark under the top right-side A-frame where the jounce bumper hits. And that's not counting the orange and lavender marks I found on the suspension. I find this stuff really neat!