i was thinking about being able to lock the drum brakes while the truck is moving. wouldn't that be the same as locking the disk brakes?

just to show you what I'm trying to do hears a picture form oldGMCtrucks.com.

http://oldgmctrucks.infopop.cc/eve/forums/a/ga/ul/3141001801/inlineimg/Y/rotor.JPG