So go to the shop, pick them up, and take them home for a workover. Knowing they are making noise, if they were mine I wouldn't put them back in without cleaning them. If the lifters are sludged up inside, physically cleaning them out is going to give you the kind of results that no "mechanic in a bottle" can.

 

^ Yes, they will be cleaned during the reassembly along with valve covers...

 

"Cleaned" and dismantled/cleaned out/reassembled are different things.
I doubt the shop is taking the time to rejuvenate the lifters, unless you specified that.

 

I spoke directly with the mechanic and suggested the carb spray and follow-on air blowout method as mentioned here:
Ccrp 1208 Noisy Hydraulic Lifters Fix 03 Photo 2

Yes disassembly would be better, I will clarify with him -- the reassembly won't happen till Monday at the earliest. Thanks for pointing out the need to be crystal clear with the shop.


PS: that film you see in the photos is just that, a thin layer of varnish, I wiped it with my finger -- I would hesitate to call it sludge, since it's not very thick.

article lifter:

 

Thing is, you don't know what the inside condition of the lifters look like till you look inside. The lifters I rebuilt were part of a neglected engine where the oil turned the consistency of congealed black tar. Everything inside the engine had to get scraped out. Judging by the black muck in your heads and lifter valley, the insides of your lifters could look like that as well.

 

^ Yea.

How much would you all estimate this job should cost including tear-down and reassemble?

Here's all the parts being replaced, GM part #s:

89017819 Lower Intake Gasket
24504789 Intake Manifold Gasket
24503377 Manifold to Cylinder Head Seal
24501563 Intake Manifold Seal
25532619 Valve Cover Gaskets
12567275 EGR Valve Gasket