Randy i would not spend a dime on new springs. you have a great spring already. I use the 02/03 springs on everything. You would not be happy with the 3400# SPRING OR THE 3600# they sit too low. I have had cars with the 02/03 springs 60 in the 1.27-1.44. Your bad 60's could be other things in your combo than the springs. Those launcher springs are more exspensive than caltracs with no adjustments. They work maybe a little better than a well tuned superstock spring set up. But if i was going to spend the money do caltracs. With that said you could have the best rear suspension parts back there and still not have great 60's if it has not been sorted out. Also you get what you get when you go to poor tracks that are not prepped good and the temps do not make for good 60's.