I run GRP aluminum in my 572.... Run em 500 passes and toss em and put in a new set..I shift at 6800 also. They key is get the motor good and warm then let it heat soak for a while before the 1st pass of the day and the will give good service..I have a brand new set of GRP pro series rods 6.760 long if interested...Paid $1250 for them will take $750