My truck...

[1972GMC350]

Hello all...I've got a problem...first a little history ..i own a 1972 GMC wth a chevy 350 with an edlebrock 1407 4 bbl carb...my truck was running rough and misfiring...but it was running, drove it daily..so i got the bright idea and spent a couple dollars and did a tune up..new parts are...cap and rotor kit, HEI plug wires , HEI/EFI ignition coil and platinum tt plugs...changed them all...so in theory it should run better...well that's what i thought...i have taken the steps to making sure timing and everything else was in order...i started the truck and had the carb adjusted and now it just shuts off like someone turned the key...I've been told its a vacuum leak that i can not find...i hear it but have no idea where its at...