Problem with power at constant throttle

[68sportsatelliteragtop]

I've noticed an issue with my car loosing power while cruising down the road. First noticed it after driving for over an hour at highway speed. At a constant 3,000 RPM, approx 70 MPH, you can feel the car kinda "nose over" but the tack doesn't budge and you don't hear a miss. If you add throttle or let up it goes away.Doesn't do it all the time. I thought it could be crap gas. I filled up , added 1/2 tank, and noticed it again, this time while running around 2,500 RPM on a local 20 mile trip. Just changed fuel filter before the road trip. Any ideas, I'm running a Holley 750 DP, MSD 6AL, and MP electronic distrib in my 383.

 

[70rr-brian]

Something fuel related would be my guess. Fuel pump, fuel filter or push rod.(assuming mechanical)

Could be that new fuel filter. Just because it is new doesnt mean it is any good. Quality control is a thing of the past...

 

[tpodwdog]

if the tach doesnt budge.....and its an automatic transmission..... you MIGHT have a torque converter issue.