Offshoreonly.com - 454 magnum power loss between 2000-4000rpms

I have a 454 magnum with 365 hp in 230 Velocity. I put the boat in for first time over the weekend. Boat jumped on plane the first time. But, next time(every time there after) it had a struggle to get on plan. Between 2000-4000rpms the boat had no power. Took 3x as long to plane off. Then it runs great from there up to 5000 rpms. No lose in speed or top end power. Checked fuel/water filter. It had some junk in it and cleaned it out. Starts like champ, idles like a champ, runs top end like a champ.

Could this be bad fuel only?
Someone mentioned a bent push rod.

Before I do a ton of work. Does anyone have a much better idea of what this might be?

Thank You.