Noises like this that come and go in the gen1 vortecs is normally lifters. It's hard to tell in your video though as that sounds like something else. Lifter noises are normally a hard metallic knock that come and go with oil pressure and rpm changes. I know my 99 has lifter problems, it will hammer like hell idling in park, but put it in gear, and it goes dead quiet. Your video sounds more like a 305 I had before with a bad rod bearing on #1. I would get an engine stethoscope and try to narrow the noise down.
Yeah, what the ferm said.
I had a 1992 with a 350 V8. It had a tick noise. Soundsd like a lifter.
Removed valve covers, started engine, soon as it got warmed a little it started tickin.
I went along and turned on rocker nuts. Got to no. 7 chlinder, backed off the nut slightly, tick went away but then it came back, tightened the nut slightly, tick went away but came back. I messed with it but could not get tje tick to quit.
Okay, removed rocker and pushing rods. Coolant pump, harmonic balance and timing cover, sprockets and chain and out came the cam.
New cam, lifters, pushing rods and rockers, along with chain amd sprockets.
Got it all back together, warmed it up, tick is back.
Popped the pan and dropped no 7 rod cap. Bearing had spun in the rod.
If I had pulled plug wires, one at a time then put them back on as I went along, when I got to no. 7 the ticknwould have gone away then I would have known it was a rod bearing.
As it was I was so determined that it was a lifter tick tjat I did not think to do a full and thorough diagnosis on tje noise.
That mistake cost Me a lot of money. I sold the truck with all the new components for dime on the dollar. I was just toondiscouraged to mess with it after that.
I do still have one of those bearing shells on tje shelf for a reminder. I can take a pic and post it for You if You would like a little encouragement on doing a full diagnosis.
