[V8] Slight surge/pulse on steady throttle

[Tom La Plante]

Hi, just  got the v8 back from ex-love of my life, and there's a  
slight pulsing at steady throttle(sport or economy mode,cruise or  
not).  It's very subtle and at idle/stepping on gas, unnoticeable.   
Runs great otherwise and mileage seems fine.  Haven't got a code  
reader yet(palm died and switched to mac so have more than one  
decision to make on that front....Anything come to mind to  
anyone?...New fuel filter ,plugs,air filter within 6 months,caps are  
20,000 old,wires original(wanted to replace at time but couldn't  
afford)  See nothing in documentation about speed sensor being  
replaced(just hit 90,000).   Timing belt/tensioner/waterpump package  
done by dealer @ 68,000.  Any ideas anyone?  Sincerely Tom La Plante