Gil Exhaust
#8
You can still run the water out through a dump on/through the transom, but it would have to be via a fitting with a hose off the tailpipe. GIL used to make these all the time back in earlier days. This will keep the tailpipe cool and safe, yet make the system totally dry, otherwise you will most likely burn the boat up the way I precieve that you were describing in your question.
#9
You can "convert" your existing gil pipes. You need to weld closed the water holes in in the outlet end. Then re drill them to about 3/32" in three places. Then weld in a threaded bung in the pipe so it will be located inside the engine compartment, this is your discharge water line.
heres an example pipes
heres an example pipes






