Mandriva is just the new name for Mandrake - they're the same company and its the same distro.
All of the Mandrake/Mandriva distros including the latest (2006) have an optional 2.4 kernel that you can install. Just head over to http://easyurpmi.zarb.org
and setup all the sources. Then in menu->System->Configuration->Packaging->Install Software you can search for 'kernel' and it should show up some 2.4 kernels in the list. In 2006 the 2.4 kernel is a contrib package, ie. not supported by updates.
Both 10.0 and 10.1 had 2.4 kernels in the 'main' tree - ie. supported by updates, although the update/support cycle for them has finished by now.