astrofast4.3

I have a 89 K1500 with a 94 TBI 350 and trans in it, i was told the motor was rebuilt and bored .030 over etc etc. I'm not sure if it has a bigger cam but sometimes slowin to a stop the truck kinda wants to die, the rpms get real low for a second and then come back up. I am a mechanic but i am new to the game and havent worked on alot of older things and do not have alot of expeirence with the TBI chevys either. I have replaced the plugs(not the wires yet) and it seems to run a little bit better but not 100%. I have heard of a couple things but i figured i'd ask you guys first, any tips or tricks or sugestions would be appreciated, i bought the truck cheap and needs a little tlc to make it a good ol girl. Thank You

grogan5

Vacuum leaks?