You can start by dropping the CAPS. Using all CAPs is considered shouting
and rude.

Jeff

First, was flooding a problem when you rebuilt the first
carb the firts time? If not, you may be looking at a
procedural problem.  Those two carbs are a bit different in
design.  The only way a carb can flood over the top is if
the float is not controlling the flow or the carb body is
cracked around the needle valve, missing gasket, etc.
Another left field type problem may be the evaporative
emissions system allowing a back feed but, I would think
this would require an over full fuel tank building pressure
as it warms to get that much fuel backed up anbd your system
should overflow on the ground first.  The only other factor
to look at here is excess fuel pressure.  Have you checked
the fuel pressure at various engine speeds?  Has an add-on
electric fuel pump been installed?  It is very rare for the
original mechanical pump on the engine to ever increase fuel
pressure as it ages but, not impossible.  An electric pump
usually requires or has some sort of pressure regulator
which may go bad or need adjustment.  Since you have had
multiple floodings with two completely different carbs, I
would think your problem is elsewhere.  BTW, the power valve
in a Holley cannot cause flooding.  It can cause an over
rich fuel mix which is a quite different condition.  Lastly,
I am making some assumptions that you are competent to
rebuild a carb and set float levels properly.  Each of these
carbs have specific methods of setting.  If you are not
intimately familiar with the process, you need to do some
research or get a manual and follow it to the letter.  Even
experience technicians can have problems in this area if
they do not have the specs or methods done correctly.

Lugnut