These links are helpful in listing what is available for Iredell and Surry Counties:
https://familysearch.org/learn/wiki/en/Iredell_County,_North...https://familysearch.org/learn/wiki/en/Surry_County,_North_C...The tax records do not appear to be online and do not appear in the microfilm catalog of those county records filmed by the LDS Church.
The NC State Archives does seem to show them, neither of which have been microfilmed, so you may have to have someone local search the records. A pdf of the available county records is here:
http://www.ncdcr.gov/archives/Public/Collections/GovernmentR...Hope this helps,
Scott