I have a '71 Challenger with 315/60/15 M.T. Drag radials on it,my problem is I'm blowing the tires of the first 60'. I had a 383 in it that pushed the car 12.25-12.30 with no tire spin at all. Now I have a 470 that is not real crazy it made 644hp/603tq. I did change the vert from a 3800 to a 4500 but the rest is the same. My best is 11.01 but my trap speed 122-124 so you see I'm leaving a lot on the table. So do you think the E.T. streets would be a better tire or should I spend the money on the suspension