Won't quit running

[CecilDunn]

Have 62 c20 had original 283 kept having problem with the truck not shutting off when key was removed also the starter would sometimes stick or keep spinning I have since done a 350 install and wired in hei distributor and alternator and have started having the same problem with it not shutting off when key is turned to off position after starting it up I have replaced the ignition switch with new keys so only thing I can think is wiring any suggestions would b greatly appreciated