We have used both 10.5 and 11s in 19 and 20s.
I'll explain why I don't have the offset data. I have used and will continue to use Forgeline on our custom builds. We do things that most others don't and always are asking the impossible from Dave (owner of Forgeline). Whe we started down this path on the G8 the consensus was it was impossible to run 275s all around on a ZETA. Working with Dave we got them to fit perfectly. We did the same with the 305s on the Camaro, then the Mustang and then a Challenger. Dave and Forgeline put in the time and effort to get the wheels perfect. In exchange I don't keep records of the offsets. I refer questions and opportunities for sales back to Dave.