I currently have the 1903's on my heads with only a few miles on them before I had to tear down the block. The only reason that I was looking for another spring was because I have them setup for apx a .590" lift and that comes out to about .150" coil bind clearance. So I thought to start looking for another spring. But if the PAC's can run with this much clearance, then I may be able to reuse them.