distributor and timing 1996 yukon

hi, just got done doing the intake manifold gasket fix. that seemed to go ok but am having issues with motor stalling sometimes when started. no backfire and seems to run ok other than the stalling now and then. is there a wire to unplug to set timing on it?? also dist is making a fast ticking noise. almost like a ticking purr. i can hear the noise from inside the cab. i dont remember this noise before. the noise seems to get louder and then stop when the key is turned off and everything powers down. is it possible that the dist is not seated all the way down?? i was reading there is sometimes issues with the dist dropping all the way down. would it run and have oil pressure if it wasnt?? the noise doesnt seem to change pitch when reving the motor. just seems odd that it keeps making the noise untill everything powers down,,,maybe a second or two after motor is shut off.

any ideas would be greatly appreciated.