I had Gates belts on my 1967 Dart and would get a squeal every time I revved up to about 3500 RPM. Not an attractive feature for a muscle car that would exceed that RPM on every outing. No matter what adjustments I made I couldn't get rid of it - I noticed the belts looked to thin and had the V-Belt guys help me find a wider substitute. I just received and installed the substitute belts and wow what a difference - no squeal at any RPM. Great service and a bargain price - I'd have paid twice that! Thanks guys !