From 68040 User Manual Section 11...
Maximum Operating Junction Temperature 110°C
You should read all of Chapter 11 as it has more information. The manual can be downloaded here...
http://amiga.serveftp.net/datasheets.htmlIt's called a datasheet on this site but it's the same thing.
I wouldn't try to push overclocking the 68040 too much and that's with excellent cooling. Some of the later 68040 masks were pretty overclockable and some of the early ones would barely do 40 MHz. It's better to convert to a 68060 and get one of the newer mask 68060's and you have something 3 times as fast and cooler than any 68040@40MHz
.
