question

a kind of a stupid question, but can any one tell me where i could find dehacked files (*.bex)?

If you can wait a time, I'll be able to finish my Doom files section of my web site.

http://members.xoom.com/mega64

There are some .deh files (not restricted to boom only) all over the place- e.g. http://www.yee-haw.co.uk/dntemp / , also check

ftp://ftp.cdrom.com/pub/idgames/utils/exe_edit/patches/ or your local cdrom.com mirror.