500 seriers cutterbar tilt questions

Cut beans yesterday and 1st time using new to me a 500 series 20ft head on a R50. this head is a SCH setup with a new sickle and guards look great. It left a ragged cut and would like to cut lower. By lower I mean the feather sheets need to be flatter. It cuts the stalk low enough. #1 looks like the guards are slightly pointed up. what is the recommended tilt. I don't have any rocks. #2 Read the adjustments in the book for down pressure on skid plates and my springs are roughly 2 5/8". The ground is very soft and I never pushed any dirt once or leave marks. I'm thinking it could have more down pressure. #3. I'm running in the low position and my old 300 head would go lower, problem is beans are sitting on the feather sheets and i have to power down to feed better. Reel is about as low as I want to go as will almost get into guards when I power it down. I feel it needs to go down about an inch to flatten out better. I haven't check the deminsion of the rod to the the 3 springs on the header height control. Do you shorten or lengthen a tad to go lower. Otherwise it floats great across the head. Also beans stems were tough which was probably most of the problem, but got a little time to tweak. Thanks Greg