I think Houston was without classical for several years after KLEF flipped.
Not so. On March 10, 1986 the old KLEF 94.5 announced it was changing formats. The actual format flip took place at 6:05am on March 13, 1986, and the station became soft AC KJYY "Joy 95." The entire KLEF music library was donated to KUHF, which was then running Jazz outside of its morning/evening news blocks. The following Monday, KUHF started running Classical 9am to 4pm, while keeping Jazz for evenings and overnights. The Classical programming resulted in a big increase in donations to the station, and by the end of the year the remaining Jazz programming was replaced with Classical, while retaining the morning and evening news blocks. This program structure continued for the next 25 years, until the launch of KUHA and the separation into News and Classical stations.
Meanwhile, the old KYND 92.1, which had been running an Easy Listening format, flipped to fulltime Classical in early April 1986, using prepackaged recordings with canned intros and outros. Initially they called themselves "K-Y-N-D, your KLEF music station" as they awaited a call change. Several weeks later 92.1 acquired the KLEF call. When Michael Stude bought the station in the fall of 1987 the call was changed to KRTS. The station went through several signal upgrades over the years (the change from a Class A to a Class C2 in the early 90's resulted in Stude donating the 50kw 91.7 transmitter facility to Rice University and KTRU in order to keep within signal separation rules. KRTS eventually was upgraded to a C1.) The Classical format continued on KRTS until 2004, when the station was sold to Radio One.
The original KLEF 94.5 went on the air in 1964, but there had been some previous Classical outlets on the Houston FM band. I believe KRBE was Classical in its early years, but not sure when it changed (There is info online but I don't have time to look it up.) Perhaps there are some oldtimers that can fill in the pre-KLEF Classical situation.