OK, I'm not to familiar with Chevy engines, I've got the stock 2.8 that came with my S10 Blazer and the engine is starting to knock, And I know that on alot of engines you can adjust the rocker arms/rods, is this possible for the 2.8? I'm wanting to try this to see if the knocking goes away, butI don't want to tear the heads off to check in case they are not adjustable.

 

A valve train noise is very rarely described as a knock. More like a tick. If you have a knock, that typically points to the bottom end, think rod bearings...

 

Alright I'll check again, thanks for the info.