the aluminum is fastened with stainless hardware. the only thing that would be worse from a galvanic standpoint is if there was a copper washer bolted between.
check with a piece of fishing line.
usually with compressed air, you cant tell where its going or if its partially blocked.
another trick I use is a can of WD-40 and making sure the oil comes out the correct passage. however that doesnt ensure the passage is fully clear.
that is near the bottom of your hull.
keep digging and removing boat bits until you get there.
the areas circled in green need to be removed to get to the inside of the hull
stay away from harbor freight grinders unless you buy the warranty. they usually smoke on the first time you use them. I have an old craftsman (relabeled dewalt) 4.5" angle grinder that is over 30 years old. it has been re-greased 4 times, and is on its 3rd chord. it has ground welds on...
There should be an adapter on the intake that can be removed to bolt on a 4-barrel.
There are only 2 gaskets needed to go through a Holley 2300 2-barrel. Most of the crud will have blocked the metering plate passages. If you do a whole teardown there are only about 6 parts on the carb
