HELP!!! 93 f450 PS where the heck is the vacum line vac/o hydraulic install

[netpro]

i hope this is the right area to post this question ...if not i'm sure someone will blast me for it ...as i'm pulling my hair on this one .. thought it would be easy

i have a 1993 f450 super duty with 7.3 in it and just got a heck of a deal on a 16 ft trail king tandem axle trailer with vacumm over hydraulic brakes ... and NOW i'll be damned if i can figure out how to install the controller in the truck the controller needs to be installed in engine compartment and connect to the vaccum ...where heck is it .....

i talked to a guy that had a dodge cummins diesel and said it had enuf vaccum to operate a similar system ... don't let that dodge show us up that would be embarrassing eh

[StarDriver]

Never heard of vacuum over hydraulic, I've heard of electric over hydraulic trailer brakes.