98 GT Lifter Tick or Something Worse? Options

[holymatt123]

Hey guys, new to the forums here! I'm not really sure if my Celica necessarily qualifies as a 6th gen, seeing as its a 93 STX body, but it does have a 98 GT engine in it but I digress. The reason for my post today, I haven't been able to drive my baby since I picked her up last week due to (what I'm assuming) is a horrendous lifter tick. I'll link a video so you guys can hear the noise as well.

GT Lifter Tick

I guess my question here is, what do you guys think this noise could be? Its originating from in between cyl 3 & 4 from the head. I'm going to go pick up a set of feeler gauges from AutoZone today so I can measure clearances. I'm kind of dreading a valve lash adjustment on it due to the fact that our cars have shim over bucket style lifters, I've heard it's a major PITA

Anyways, thanks in advance guys I'm looking forward to hearing yalls opinons.

[Box]

Hard to tell from a video, but it could also be a leaking exhaust manifold so I'd check that first since that's easy in comparison.

Oh hey, you're like 30 miles from me, small world.