How low with stock front inner fenders?

[muddpile]

I'm planning on putting 3" drop springs in the front of my 72 to complement my 2 1/2" drop spindles. Wheels haven't been ordered yet, but will be 20x7 with 4 1/4" backspace and 225/35/20's on the front. Anyone gone this route on a 5 1/2" drop with success and little/no rub?

Also, in the back on a 7 1/2" total drop (Flip kit and shackles, already in), would 20x10 with 5 1/2" backspace and 275/40/20 fit alright?

Right now I run 15x8 rallyes on all 4 corners with 255/70/15 rubber on them. Rear is good, front rubs pretty bad with the current 3 1/2" drop.