Perhaps I can add to the discussion. I am using what I can recall if things are incorrect please respond.
I don't have years down I can give a bit of a timeline. WLUP-AM set it's sights on daytime only WSCR which was at 820 at the time. They thought the powerfull 24 hour signal it would be easy, it wasn't.
Both the AM and FM side had made changes previous to launching Sports 1000 WMVP, ESPN was not in the name. Johnny B. was doing the showgram morning on both the AM and FM. The show was on 5:30-10 the stations would split at 10 with Matthews doing 10-2 and Stroud taking the FM from 10-2:30 when Skafish came in. Steve and Garry did the afternoon show after Matthews on the AM.
At this time the FM was a mix of classic and some current rock. It was a very good station. In 1996 Evergreen(now part of the Clear Channel consolidation) bought WWBZ 103.5 The Blaze. The Blaze was a hairband rock station with some classics thrown in. It was very popular at first, it was the number 1 rock station in Chicago for a while. They were very repetitive and had a very tight playlist, which caused a lot of people to go back to WCKG and The Loop. You can only hear Crazy Train every 2 hours everyday for so long.
The station was still not doing bad however. It was losing steam and it was the only station in the market owned by the company who's name escapes me now, Dennis something? broadcasting? They cashed out and Evergreen took over. At first the station stayed the same, it eventually came to be called Pure Rock 103.5 The Blaze. Scott Loftus of the old WVVX was hired for evenings.
The plan was take the Loop AM to sports, The loop FM to a comedy, man talk station and bring an active rocker to 103.5. At this point Q101 was the station to beat.
Steve and Garry moved to mornings on FM, and the stations tweaked the music a little younger, taking out a lot of the classic rock. When the decision was made to go sports Coppick was put on AM in the afternoon slot. The Blaze had now became Rock 103.5 with Mancow in the morning. The FM loop had Steve and Garry mornings, Matthews midday and Johnny B for the drive home.
Cochran who is on WIND now was brought into to do nights, Danny Bonaduce was from what I recalled brought in for afternoons I believe this was when Johny went to LA.
If you remember Steve and Garry had their fight and broke up, it ended up with Dahl doing mornings on AM with Bruce Wolf, Matthews got mornings on the FM and Garry was put 10-2 on FM.
The sports format had low ratings, Dahl was actually the only thinh holding the station together. The FM was starting to play more music, the same type of new music The Mix was playing. This was when the Mix was really starting to turn into a powerhouse that it remains today.
The AM sports format was dropped except from 7-midnight were they put Coppick. I think Dahl and Wolf were let go at the time i am not exactly sure on that. The simulcast ended around Thanksgiving, what year that was espaces me.
The FM became "Johnny B in the morning and " The best music on the planet" the rest of the day, who thought of that slogan is beyond me. The music was almost identical to The Mix. The AM featuered Matthews from 1-6 PM and Fred Winston got the midday show.
The station kept the WMVP call letters, they just called the station AM 1000. In time the Loop FM was bought by Bonneville and the loop was changed to "Classic rock that rocks" this was to keep the Mix rolling forward and it worked.
Johnny B was put in mornings on The AM. He was not part of the sale to Bonneville. The AM side would soon be sold to ABC and everyone was released and it became ESPN 1000.
I know there are some holes in my story that hopefully someone could fill in. This is what I remember from the stations I hoped it helped more than confused.