Lets not jump to conclusions and assume this is bad lifters.
While its possible and they are known for this start small and work your way up.
Is your oil pressure low?
How is your oil maintenance on this engine?
Do you use proper weight oil and a quality filter?
Could be an exhaust/exhaust manifold leak?
Is the noise constant, change with rpm, engine warm/cold?
I would get an automotive stethoscope and try to narrow down where the noise is coming from. Could be the lifters, injectors, exhaust leak, transmission. Poke around and see what you find.
Maybe change the oil filter and add a quart of trans fluid and drive it for a few hundred miles and see if the detergent in the trans fluid will remove some built up sludge, then change the oil and see if the noise dissappears.
Spend $50 first, it may be something as simple as what I said. Dont automatically assume it will be a $3000 repair.
does it sound like these?
https://www.youtube.com/watch?v=vyhl7N6WVbI
https://www.youtube.com/watch?v=4RecrxxLT4s
