As promised, here are pics of my new thermostat burper. I got one at River Marine Supply here in Miami. Notice how it turns sideways so I can still step on the PCV? housing (strong spot) at the top of the engine. Have tried it a few times and works great.

I also bought a new 3" Heat Exchanger from go2marine.com. It's the SeaKamp described in other threads and/or the tech maintenance section. I opted for the cuprous nickel, which was only a few $ more.

It also has a much larger pencil zinc than the original 2" heat exchanger, so hopefully I won't have to change out that zinc so frequently.

Installation was quite easy. Fit in there quite nicely. Also replaced all the cooling hoses.

Will take it out for a sea trial in a few weeks.

BTW, the RydLyme procedure (in my other recent thread) did drop the temp about 10 degrees at 2100 rpm, but it still was up around 190, so I'll let you know if the larger heat exchanger solves the problem completely.