Move the crossmember?

[2wd73blazer]

I am in the middle of building my 71. I have the cab and bed off the frame while I am working on it. I installed a CPP drop crossmember and tubular trailing arms. I went with ECE 6" drop springs, track bar, and shock relocators. I was wondering if I needed to move the crossmember back some with a 6" drop to keep the wheel centered in the wheel well? I know some of the guys bagging their trucks do it but I dont know if I need to since I am only going 6". I will be running 22x10 rims on the back and would like to run a 305/40 tire which has a sidewall height of right at 5 inches. I need my wheel centered to avoid clearance issues.