[Discuss-gnuradio] How to use Correlation Estimator Block

Hi, I want to correlate my data frame with known preamble , i am using CORRELATION ESTIMATOR BLOCK . it has two output ports one is for correlation and one is shown as output port . I want to Know How to Proceed further for synchronization ,Which block i will use next to it ,which should remove preamble by estimating the peak of correlation and extracting data out of it. Kindly check my flowgraph , Your help will highly appreciated ,Thanx