1973 225 valve adjustment help!please!

i have new plugs/cap/rotor/wires and it does have somewhat of a rythym to the idle. i bypassed the vacuum lines going to the firewall. i can tune a four barrel 318 or big block all day but these sixes seem to be a little more tempermental but it could be me. i noticed a change with the idle rythym after i messed with valves . could that be related? i can hear kind of a puff with a couple cylinders but not a solid miss . from my v8 experience its almost like a timing issue but i did not notice it before the valve adjustment. the previous owner kind of mickey moused a few things but it has a brand new holley one barrel and has worked great so i ruled that out as a possible mixture issue. i will get it exactly on top dead center and see exactly where the rotor is and go from there. i like to advance the timing on my v8s so i wanted to do that anyways as i pretty sure it is still at the factory setting. thanks again you have given me much insight!