are the ar 30 round mags that don't have a date code on the body ok in ban states that allow pre ban mags?

A particular state's list of unlawful firearms would include specific items. If you find a list that includes mags with date code, let us know. I would be surprised to see it.

By default yes...if a mag body is undated and larger than 10 rounds it's considered pre-ban. I don't think there's been any mags made since 1994 that haven't been dated, at least not in the US, and I don't think mags can be imported unless they have a date code on them, or are known to be from before 1994?

I have a bunch of pre-ban AR mags I've been sitting on as well as a bunch of pre-ban AUG mags as well...

Most states that have an AWB modeled it after the federal AWB, which has clear verbiage that any mag made after 9/13/1994 is considered "post ban" and must have a capacity of 10 rounds or less...and any undated mag is presumed to be manufactured before that date, and therefore legal/grandfathered in. I don't think any of the states have really changed that verbiage, but I could be wrong..