Cooling issues

I have a 5.9 360 transmission was giving
me some problems so swap with another
one was getting the trans temp light except
all cooler lines felt cool to the touch after
flushing everything and all that decided to
cut out the check valve in the cooler line no
longer did I get the trans temp light which
was throwing me into limp mode but
suddenly under the engine compartment
seems very hot as well as the top radiator
hose in the right side being the driver side
of the radiator seemed hot higher than I've
ever noticed it before anyway decided to
put cooler line with new check valve on and
the trans temp light remained off which at
the time was the only problem I was having
because it was throwing me into limp mode
but still things seemed extra hot under the
hood now was driving on the expressway
and suddenly would not downshift it was
like I was driving a manual and let off the
gas in third going 70 so the gist of what I'm
asking is I know for a fact things are too
hot under the hood and it's causing a
problem in my coolant system obviously to
where the transmission itself is having side
effects but I'm lost because the trans temp
light is not coming on as well as my
thermostat stays consistent and doesn't
overheat as far as the gauge goes before I
get back out there and tear it down again
I'm just looking for a directions to go
whether it's the fins on the water pump T
rated radiator hoses vacuum lines pressure
whatever which I did pressure test the
radiator yesterday and it was holding at
most 2 pounds less than the max but still I
believe 16 which is what it's actually rated
is within spec well pressure testing only
leak detected and by leak I just mean it's a
wet spot it wasn't actually leaking at the
moment was on bottom side of water
pump unsure if that's enough to lose the
pressure I'm just looking for advice before I
take off the radiator the water pump and
everything else so any help would be
greatly appreciated