I know that milling a set of heads will raise CR, so this is kind of a "check my math" type question to make sure I'm understanding how the valvetrain works.
After a head is milled, and the stock length pushrods are used, would there be an increase in lift at the valve?

 

No, you'd have more lifter preload though. Or if you milled it a whole lot you might bottom out the lifters and start hanging the valves open when the cam is on the base circle...

 

Theoretically, if the lifter was unable to absorb this extra length in preload as stated above, then yes, you could get more lift. The MAJOR downfall is that the valve might not close all the way causing it to burn up and fail very fast.

 

I haven't given any thought to the lifter's purpose, which is why I'm glad I asked this question.
I don't understand the lifter's purpose in the valvetrain...in my mind, the cam lobes tap the pushrod, which lifts the rocker, which pushes the valve(s) open.
I have alot to learn apparently, any information is greatly appreciated.

 

Cam lobes don't tap the pushrod...there's a lifter in between