Is A frame notch always NECESSARY?

[jackedup]

I'm wanting to lower my 71 c10 with 4 in. lowering leaf springs and drop spindles in the front. My question is for anyone who has used the 4 in lowering leafs and if they had to notch the frame to create more clearance or did the springs just go in with no other mods needed. I always prefer not making too many mods so if in the future I want to restore it back to the original stance, it still looks unmolested with regard to the frame.