We ran the stock shafts for years the clips never marked them the rocker started to mark the shafts but only after I started to drive it on the street.we made new shafts they must have over 8000 miles on then,but we did back off the spring load.We did run 612's crane on the street back when my son was 12or13 when I put the 660's back in the eng when I sold it he did not want me to sell it.I think it is in a falcon in Mishagan near milan. John David is 34 yr's old now.
