Very simple plugin to change the version number in 3.90 M33 System Information, enable the plugin and create a vchanger.txt in the root, which you fill with the version you want. It doesn’t need to be a numeric version, you can use anything you want, even complete words But the maximum it can go is 10 bytes, not any longer.

http://forums.qj.net/f-psp-development-forum-11/t-release-flashless-version-changer-v2-slim-support-134576.html