Broken Springs Need Lift Advice

[BRS]

Finally got around to putting my 4" ProComp lift on my Early '99 and ran into a problem tackling the rear. Drivers side has a broken rear leaf in the middle of the pack, and the passenger bottom heavy leaf is broken too. The ProComp 4" uses a 1" block and an add-a-leaf for the back, so I'm stuck. I can track down some replacement stock springs, but that seems like a waste, so I'm thinking about ordering some 4" lift springs but not sure. A lot of rear 4" lift leaf packs require the stock bottom heavy spring to remain (instructions for procomps 6" rear leafs), but one of mine is broken of course. Also, I have an Early '99 350 with the 4" block, so I need the math to work out right. Would it be better to get much taller springs and throw the block away? Any advice folks?

Thanks!