I know that due to the change in the distance of the o2 sensors from the exhaust port that tuning is recommended when going to longtube headers. What usually gets changed though? Are you re-mapping the VE table or is there something else that gets changed?

 

Long tubes will "usually" improve the ve, as in leaning
the AFR.
The O2 sensors are still doing the same job.
Suggest data logs be looked at to determine the changes needed.