Pressure test is definitely a way to go. I'll see whether I can do it with
the addition of some simple tools. What I'm not sure is how will I be able
to find out what the exact spot is. Even without doing it I know the engine
will fail the test but I'm not exactly sure how to proceed afterwards.


Why? All you need is a non-relieving cap with 1/4" nipple, available
at NAPA for less than $10, a low pressure gauge, and your air
compressor, even the little tiny ones will work.

Some people like to use the tool designed for the job. For less than
$10
and no time expended, you can rent the tool.

The tool I've described IS "designed for the job". For less than $10 you
can OWN it.