Is your PC using the K6-2? I have read that the K6-2 has a much lower performance than Pentium 2 with recent kernels. This is what worries me.
But I may not understand this well.

English is not my native language.
Don't worry, my native language is Spanish (Castellano, o "Español"). That's why I write here using a translator to improve my rough English. I have a PC with an AMD K6-2 for testing with different distros, software, etc. Installing modern distros as Salix is perfectly possible, but you have to configure a lot to work well on older hardware. As I told you, one way is disabling system services that are unnecessary. Another way is to install lightweight software (Example: Midori instead of Firefox, Abiword and Gnumeric instead of LibreOffice, Xmms instead of Exaile, and so on.). Anything that allows you to save ram
But there is something that thenktor is right, and is in the fact that the performance of the machine will not be "ultrafast". But it's always good to test yourself to see if the experience satisfies you. In this area, I have tried other distros that are optimized for older hardware (kernels for i486 architecture.), mostly based on Debian (except PuppyLinux, i think):
GALPon Minino (i486 version runs ok on K6. i686 version requires Pentium II or III. This distro uses kernel 2.6.27.2, it is based on Debian 5.0 "Lenny". The next version will be based on debian 6, probably.)
antiX (i486 version runs ok on K6)
DSL - Damn Small Linux (based on Debian and Knoppix, for older...older...PCs than 486, pentium I and AMD K5).
Molinux Zero (Spanish version of Puppylinux 4.3.1)
And there are some based on Slackware like:
Vector Linux Light edition 6 (with JWM and IceWM as window managers. The installer can set all the services, software and tools you need.You choose.)
Absolute Linux (I have not thoroughly tested. I could not make it go on that machine. You may need a Pentium III onwards)
Delli Linux (discontinued)
Basically you have problems with those distros that only provide a kernel optimized for i686 architecture. With the i486 architecture and generic kernels will not have problems. In Salix, the kernel for old hardware is called "huge.s". In short, you should do the test because it does not work, you can always use the pc for any other use: test machine, asleep terminal, server, firewall, among other uses.
Greetings,