engine won't stop

[69gmcbigblock]

hey all,

so my truck suddenly does not want to stop. so today i picked up a new ignition switch and installed it. plugged it all in and the same thing. it starts up fine, just won't stop when i switch to off.

it doesn't sounds like deiseling, but i guess it could be. it just keeps running if nothing has happened. the only other odd thing is that around the same time it started happening i got a nasty exhaust leak or something because it is suddenly really loud...but i've yet to find the big rust hole i expected to find.

any ideas?

cheers
droo