I've never heard of the a833 in a chevy truck either...not saying it didn't happen...just never seen it....when I google it ,it shows it to be a side shifter....and belonging to dodges...then after some reading I saw on hamb where they said Chevy used some dodge trans in some trucks and vans...and this.....
http://www.classicjunkyard.com/new_process_a833.htm
My 86 had a sm465