How far forward to center the front wheels

[jkb]

Installing a 87 crossmember and gear in my 65 chevy soon and was wondering how far to move the front wheel center line to best fit the wheel opening, I'm running 16" steelies in the front if that helps lol, and no idea on the tire size yet. Also has anyone ever just cut out the old frame and spliced in the whole sub from a 73-87? Seems like it would be less work and all the steering and everything never was disturbed. I've done a few front subs on 55-59 trucks with a camaro and always had great results. Was thinking of Z'ing the clip in about 3". Your thought and ideas, references would be of much help. thanks!