I am referring to something even earlier than even this because it really was only 1-5. It may not have been CBS exclusively nationwide. The 1-8 you are reffering to is probably the same package that TNT had later on.
Same syndication package
Lorimar started repackaging seasons 1 - 8 in 1985/86 and the syndication runs on the local stations started from late 85/early 86. Not a great success so many stations dropped it quickly. Also see
@knots4309 post about the Lorimar changes and the subsequent decision to stop the repackaging. Only 160 episodes (to the end of season 7) were made available to local stations and even TNT at the end of 1992 was only offered the same 160 episodes. In 1995 TNT finally managed to get all 344.
A few examples of local channels running the syndication package on weekdays were:
KTTY 69 San Diego (IND) at 10am from January 1986
KAUT 43 Oklahoma City (FOX) at 10:30am from January 1990(!)
WTVX 34 (IND) West Palm Beach at 11am from January 1989, directly after syndicated Dallas airing at 10am
WPDE 15 (ABC) Myrtle Beach at 7pm from January 1986 (Dallas at the same time aired at 10am on WIS 10 (NBC) and Dynasty at 4pm on WCSC 5 (CBS)!)
WMUR 9 (ABC) Boston/Providence/Manchester at 4pm from January 1986
WDZL 39 (IND) Miami at 11am from fall 1987
WXIA 11 (NBC) Atlanta at 4pm from early 1988, after the soap block of Days of our Lives, Another World and Santa Barbara
WMOD 43 (IND) Tampa/Orlando at 9pm (two episodes back-to-back) from January 1986
So completely all over the place and as early January 1986, possibly even fall season of 1985. If I remember correctly, the syndication package was cleared in around 60% of TV markets at its peak.