so my trick to a clean chop is using an 86 or newer truck with bolt in quarter glass. unbolt the glass, replace the weather seal foam on the glass for later. I cut the roof at the foward edge of the the curve for the window. i also cut the C pillar even with break of the window line. This gives you the most top material to work with. Like i said earlier, if you cut carefully you can use only one truck. (I think). The new drip channel for the rear of the cab is a hurdle still. i didnt like how this last one held up. one year and it tore. I also cut the gate under the window. basically cut the flange off the bottom of the window, straight out to the edge. then filled it back in with new glass mat. I sloped the top of the lower gate section toward the outside to match rest of the body line,and it improved the seal to the glass. Il get some pics on to shom this soon.