When you lower with springs only, it does change the alignment so you would have to realign it after the install. Since you've already got them in, it doesn't matter. Lowering spindles on the other hand do not affect the alignment geometry at all.
Good job going with ECE for your parts. Top notch company, can't say enough about them. All of my suspension parts come from them too. I normally stay away from CPP as well, although I do have their rear sway bar. Make sure you add that rear sway bar for those road courses there buddy
