I have an intermittent lifter sounding knock like the one of the lifters is not pumping up all the time. I was thinking about replacing the lifters and pushrods to see if it fixes the problem. Is it possible to replace the lifters thru the head without removing the intake? I know some engines this is possible but will the lifter fit thru on the 3100 motor? the motor has approx 175K on it. I just want to limp it back together without investing too much.

Please help.

Nope, sorry, not possible