Sounds like that was a lifter as an oil starved rod bearing will only get worse over time. Any future thread readers take note the lifters are in the rocker arms just under the valve covers, if its louder under the hood than under the truck its likely lifters over rods making the noise.
Glad to hear ya had a good trip smile

89 v6 Raider 5spd
89 v6 Montero auto
86 TD Trooper