Did you test the oil pressure? its expensive to replace parts without diagnosing first, even more so when you are paying someone else to spend your money. They have every incentive to spend more not less.

There are three basic causes for ticking:

1. Lifter/rocker tick - Most commonly caused by low oil pressure
   1. can be caused by broken oil pump gears - most common - 1 of 24 for me.
   2. Can be caused by walked cam bearings - visible from bottom with oil pan off or top with lower intake off - caused by overheating - I also had exactly one in 24.
   3. Can be caused by worn rods or mains, never had that and I have had a dozen over 150k and several over 200.
2. Slipped liner - usually only happens after engine reaches temperature about 190-200.
3. exhaust leak - usually at the manifold pipe juncture - can be tested using shop vac/leaf blower.

 

Was it ticking BEFORE the replacement? If not, that's your answer.....
Most mechanics don't take the time to set these assuming the 'hydraulic lifters' will auto correct for all of the new rocker heights....they don't

PS: do you still have the old ones??? if not, In future, always ask to keep old parts....sometimes, they are still good...

 

@Liz Ok all of us answering are making an assumption that you know the parts of a pushrod V8 that is our bad.

There are 4 components that are related to the tick each one is seperate :

1. Rocker arms
2. Pushrods
3. Lifters
4. Camshaft

Most likely you had the rocker arms replaced that is simple and takes maybe 2 hours,and each side is a complete assembly.
Pushrods can be done at the same time as the rocker arms, but unless they have severe wear that is uncommon.
Lifters and the camshaft are normally done as set and that is a big job, 5 or 6 hours plus run in time. Due to wear patterns lifters are rarely done without doing camshaft.

Lifter tick is normally caused by either weak lifters that can not build enough pressure or worn rocker arms. In both cases the tick as actually caused by the pushrod not being able to maintain contact with both the rocker arm and the lifter, a gap is created and the tick is the rocker arm striking the pushrod. Although the pushrod, lifters and rocker are separate parts they are supposed form a basically solid assembly.

 

Can you show us the receipt for the work done by mechanic that replaced "the whole assmbly" (quote from your 1st post). Want to see what he replaced. Replacing the lifters means pulling intake manifold, rocker arm assembly is a little bit easier job, throttle body plenum, tappet covers and you're in there. So, when you write he replaced entire "assembly" that kind of means...just the...rocker arm assembly to me.

Had a tech, fresh out of UTI, that put new lifters in bone dry. Started it up and it clattered like mad. Brought me right out of the office. Anyhow. Asked him if he pumped up the new lifters before install. He said, "oh, they don't do that anymore." I'm like..."did you just see a turnip truck drive by and believe l fell off it?" To this day, this vehicle sounds horrible, shop truck. Could you imagine a custumer paying for such shoddy work.