Just ccurious,what brand & grade oil are you runing?
Are you sure it's valvetrain noise and maybe not detonation when bike is under considerably more load with windsreeen and heavy head winds at 70mph?
The valvetrain doesnt care if the motor is under load with heavy head winds or under lighter load with no headwind,if vlqve are out of adj they will make ame approx noise lvl at same speed reguardless of load motor us under.
But if you running motor oil that tends to thin out when motor is under a heavier load at higher speeds of 70mph having to use more throttle with heavy headwinds making the motor run hotter that can cause the hyd lifters can get a little noisier if the oil thins out dropping out of its original viscocity index for ex from 20-50 to thinner 10-40 which can happen.
The thinner oil causes a drop in oil pressure,but drop in oil pressure with hot motor can also be a result of a somewhat worn motor that hasnt had regular oil & filter change maint where lower end beraings/oil pump clearacnes etc have opened up a tad due to more wear then usual from poor oil maint causing hot oil pressure to drop too.
But a valve adj done properly would never hurt anything either.
,i see a lot of guys writing in here in RSC that their R*'s motor make plenty of noise esp in the top end-valve train area,my 06 1700 with 6,200 miles on it runs very quiet even when hot ,i run Mobil 1 full syn V-twin 20w-50 oil.
Also,if runing 87 oct fuel if the carb
is setup slightly lean with having to run the motor harder heating it up more under heavier throttle & load when riding in heavy headwinds esp with a windscreen it could also be detonating which to some people also sounds lke detonation too.
Just for ha ha's try some 89 or 91 oct fuel to see if that will stop the nose if your not very sure it's in fact valvetrain noise your hearing,won't hurt anything to try it.