Ford F150 Ticking

I have a 2006 Ford F150 69,000 miles. Cranks and runs great, BUT after it has been driven about 20 minutes it gets a ticking noise down low in the engine and gets real sluggish when you step on the gas. The dealer has replaced all lifters 3 followers and cam phasers on right side and its still doing the same thing. HELP

One of the first things I would wonder about - b/c of the sluggishness after a while - is a restricted exhaust system. I can’t connect that to anything specific that would tick but excess back pressure can do all sorts of funky things. This can easily be checked with a vacuum gauge though there are also gauges made to directly check this.

There are certainly other possibilities - what did the dealer check and (presumably) eliminate before doing all of that engine work?

They did a lot of diagnostic test and said if what they where doing did not work, that they would have to pull the head $$$$$
When they first got it they thought it was a bushing that had fallen off the crank shaft but after they dropped the pan said no. After replacing all the stuff lifters… it has the same problem only milder. i have pd $1050 and am not excited about paying to have the head pulled thanks for any suggestions