Just got back from test n tune and i have a question. I changed cams from a MP .508 that went soft to a Comp .508. No other change and I did not swap the 5 year old valve springs. I encountered a lean pop anything over 6000 rpm in the top of any gear. I thought it was just lean and I jetted up, 2 sizes up front and 4 sizes out back and no change in the lean sputter or pop. BTW the car did not slow down either??? Are the springs shot with the new cam even though it is no bigger than the old one??? I did make a gear change a while back and before the car never went over 6100 with the 4.30, now with the 4.56 it traps around 6400 rpm missing from 6000 up. I let out everytime about a 1000 foot. Any help?