Leaf spring question, Arch being an issue?

How much of an issue will it be if i use a main leaf that has less arc than the rest of the leaf pack??

I had two packs of leaf for a lift, and had one main leaf that had a crack halfway through it and was concernec about the difference in arch's between the rest of the lift pack and that of a junkyard leaf for the main.

If you're going with the Rocklizard BB, arch shouldn't affect you, but your 2nd full length main leaf HAS to extend all the way to below both sets of spring eyes. Take the cracked pack back to the junkyard and get your money back.