your crank sprocket has 3 keyways, 1 will be for zero advance, 1 will advance the cam, and 1 will retard cam timing. look at your instructions or online for which 1 does what. also you can get bushings for the cam sprocket that will allow you even finer tuning. If I were you I would go with what you have. 1 degree will not make a significant difference on a street motor. by the looks of the slop in your old chain, just replacing it will make more difference.