U-clips along the bottom/rear of the quarter panel ( 2 per side)
Mount valance to body attaching it to the vertical braces with 10-24 machine screws.
install double ended studs in 1/4 panel to valance U-clips and install nuts with free spining captive washers to secure the valance to the 1/4 panel
I'm not 100% sure what years takes what style - but I do know some take a phillips headed machine screw and some take a hex headed machine screw to attach the valance along the top to the bottom of the tail light panel and same screw for the valance to re-inforcement brackets
RT Specilaties Picture