Appropriate Wheel Offset for 18" Wheels?

ya, the 69' I'm doing has an early K, should be the original /6, but there was no motor so I still need to confirm that. choices being a full 73' up K and steering linkage. or keep the 69' K with /6 to SB conversion mounts and add 73' spindles. then I would use the hotchkis front bar so it wouldn't be so wide. probably going with firmfeel upper arms. cars going to see alot of street driving. guess i'll call FF and see if they know how the drdiff 13's fit rear mounted...
I love doing this, but it's a pain deciding which way to run when nothing's locked down yet :)