Pancaked Xmember Question

[Realnoisy]

Hello Forum,

I have a 1965 C10. I'm converting to a 73' xmember, power steering, & disc brakes.

I pancaked my xmember 1.5 and have 3 inch dropped spindles running 28 inch tires. I haven't installed the xmember yet and reading the forum I'm a little confused if I need to move the xmember 1 inch forward the rails to center the wheels in the wheel wells. I have read that this should be done when z'ing the frame but unsure if this is something I need to do with a pancaked xmember.

Since I haven't installed the xmember and power steering unit yet, your comments and advise would be very helpful. Thank you.