Tom, I had the same results when I did mine..the window still tipped down in front when going up. I used a Dremel and elongated the front hole about 1/4 inch in the SBC bracket making the hole lower. When tightening the bolts I just force the wndow up in the front bringing the bolt down into the elogation then tightening both bolts. That causes all the slack in the guides to be taken up and puts more lift in the front. That combined with widening the track a bit, forcing the front guide forward a bit and silicone slickem my windows work great. I know you will find the "sweet spot" eventually.