hesitation

Hey all. Chevy 383 with Holley 750. This is a fairly recent issue, but when it warms up it starts to hesitate a little. Not making it undriveable by any means, but it's noticeable. Just replaced the spark plugs about a month ago and it was running great. You think that has anything to do with it?

any ideas. my 68 camaro with a 350/350 is sluggish and hestitates when i accelerate? i replaced the plugs, the cap the rotor. The carbuator, the distrubutor and it adjusted the timing, the Air/fuel and the fuel filter but it has not changed the the sluggish and hestations...what am i missing...