Yes, I replaced all gaskets when I did the head swap.

 

Flex plate?

 

already checked and tightened them

 

I need to get on mine. How difficult was it? Any tips?

 

The plate is secured by four bolts. IIRC You need a 14mm, 15mm, 17mm and 19mm to open it up and tighten the 4 TC bolts. Everything but the 15mm is for the plate itself, you can use sockets or wrenches. The TC bolts are 15 and you'll need a wrench.

 

Yes.

 

Hey man, I had the same situation very recently.
Not quite the same noise, but similar.
I bought it with a recently replaced head and an engine tick, I thought it was the lifters, but after a very good mechanic did a very good inspection of the head, it turned out the valves were seated too deep. In turn causing the stems to clatter against the valve springs etc, so badly that there was indentations in the stems - couldnt have been good for the rocker arms or lifters.

Perhaps you have the same problem? The incorrectly seated valves I had was supposedly done by an "expert"...so could be an easy mistake to make.

Heres a link to my engine tick.

 

I got the reman head from the local shop called Napa I don't know if you've ever heard of that auto parts store or not. But is it worth getting it checked? When you drove your jeep did the sound continue with the RPMs?

 

Yeah the noise continued, consistently through the RPMS. didnt really go away much after heating up at all.
I hate to say this, but you're most likely going to have to pull the head to find the problem...I noticed a lot of the same responses to my engine tick threads, and I know for the most part it generally is either lifters, exhaust cracks or piston slap, but sometimes it can be something completely different, especially in a case like yours.
So if you do pull the head, make sure to really inspect it well and take your time. Don't simply assume lifters etc.

 

Anyone else value their opinion? Should I try any additives? Maybe mystery oil? It's so aggravating not be able to drive this jeep especially since it's my daily and my pride and joy.

 

Is the new reman'd head compatible with a '99 engine?
No ticks before the head swap?
If not, then its likely related to the head swap somehow.

I don't believe in coincidence but with XJs never can tell.
Even though you tightened loose flex plate bolts, still could be a cracked flex plate.
Maybe the springs are stronger on the new head causing a weak lifter to crap out? MMO might be worth a try but i'd revisit the torque specs again first.

Don't want to scare you off but here's my mystery ticking story.
After listening to your videos again, i noticed the ticks are also loud when you stepped back towards the driver's side door.
This coupled with it gets louder the hotter the engine sounds a lot like the same symptoms my old 290k mile engine had.

With a stethoscope or use the screw driver method, determine where the ticks are loudest. In my case, the ticks were loudest at the rear bottom of the oil pan. Was also loudest at the rear of the front tire wheel well.
It got louder as time went on.

The engine started great, checked flex plate bolts and even installed a new flex plate, ran great and had good oil psi but that tick to me was a ticking time bomb.

Even had a Jeep tech and a couple mechanics listen to it. Once the engine was pulled, we did pull the oil pan, no broken piston parts and the crank had no forward/rearward movement.
Didn't want to go any further as it needed to be sent back to Chrysler as a core engine. Never did determine the exact cause of the tick.
Best guess was a wrist pin transferring the sound to the crank
New engine, no more ticks.

 

Man.. if you listen to the second video and when I rev it up hear that tapping. That's what scares me the most.. I really don't have the time or even the money to keep dumping into this thing. I just hope it's something simple as a lifter even though taking off the head is a pain because of the manifold. When I wake up tomorrow I'll take the valve cover off and pull the rockers and pushrods out to make sure I had everything lined up properly and then took them down to 20 ft lbs.

 

When you take off the cover again, i'd double check the exhaust gasket and manifold for signs of a leak, bent push rods, etc.

Also look for cracks in the exhaust manifold/header/tailpipe.
Could be the stress of removing the exhaust manifold finally opened up a crack that was ready to go at some time in the future.
Let us know what you find out.

 

I have a very similar sound in my XJ - muffler shop used a stethoscope and thought it was a crack in the exhaust manifold on the engine side of collector, a few inches above the flange to the down-pipe. Last week it got really loud and YES - now I get fumes in the cab around town. New manifold/gasket (Mopar) and exhaust seal bought and will install soon (I have a good good mechanic and wait till he has an opening this next week.) All the best.

 

So update for anyone who cares what is going on with my Jeep. Took the valve cover off and all push rods and rockers were straight.. I ordered a set of lifters and as well as new push rods to put in. Pain in the butt to take the head off again but if it fixes this annoying noise then so be it. I just miss driving my old girl lol