Funny, I have read through the ADVrider comments and scratch my head over some of the luddites' comments in opposition to the usefulness of the thermobob.
I read through much of wattman's data and reasoning. Sent him a message questioning the bypass for extremely hot ambient situations and got a reasoned response
that satisfied my one and only concern, which he admitted to also having but also showed with test data that it is an insignificant difference in coolant temperature. My suggestion was to use a dual element thermostat to force all coolant through the radiators at very high coolant temperatures but the improved cooling(2-4F) was unjustified by the increased cost($unk) I considered trying to convince the luddites at ADVrider but realized that others had already said all that can be said yet luddites gotta lud. My opinion is that the product, conceived by a ME, is well worth the cost. I am a degreed mech eng who was called a "thermo fan" by one of my college professors; also took classes in internal combustion engines and read Sadi Carnot's little booklet, if that makes my opinion any more relevant. If wattman's opinion and data and many anecdotal comments do not convince then nothing will. Something interesting I learned while researching was this little tidbit from Wikipedia: Research in the 1920s showed that cylinder wear was aggravated by condensation of fuel when it contacted a cool cylinder wall which removed the oil film. The development of the automatic thermostat in the 1930s solved this problem by ensuring fast engine warm-up.[4^ Sir Harry Ricardo - Memories and machines: the pattern of my life Constable, London, 1968. P218
The thermobob results in even faster in engine coolant temperature warm-up and also more uniform temperatures within the engines cooling passages. No brainer to me.

And on topic: considering all the issues I keep hearing about on recent 351 kits I am glad I kept my stock cylinder and piston should my BB351 crap itself.

 

Didn't say all of it made sense... some of it. If a rider has a clue they will know.