how do I tell which is exhaust and which is the intake valve with theintake manifold on?

I aplogoze in advance because this is probably a dumb question, but I
cannot find the answer to it.

I had a heck of a noise going on in my 350 V8 chevy engine. I checked
it out and one of the rocker arms was quite loose.

I am reading up on how to set the clearance on the lifters. I snag #1
cyl and get it at TDC using the marks on the flywheel. I can tell the
cyl # by the stamp on the engine block. Then I can set certain exhaust
and intakes to proper clearance. No problem since all the cylinder
numbers are marked on the head.

1. BUT how do I tell which is exhaust and which is the intake valve
with the intake manifold on? Been looking in the book and I see no
info on that.

Then I move and set it for #6 cyl and then do the rest of the rocker
settings.

2. Been wondering how come that rocker was so loose. As I understand
it, the hydraulic lifter is just an oil filled damper chamber to take
up erratic slackness within fine limits. If it was stuck it would make
a clicking noise, but would not be THAT loose? Or do I misunderstand?