Hi Dirk,
Couldn't get the reply offline to work, so here's the response:
It isn't just the adjustment!
Solid rollers do not like to idle. If you idle one of these in normal traffic you will eventually break one...
Flat solid lifters are much more tolerant of idling. This would be OK for those who love tinkering
I went to a hydraulic cam (with hydraulic rollers) to reduce maintenance overall. I have enough things to repair on the car after each track session without that!
I forget exactly but seems to me 75 or so on the highway is around 3000 rpm. There are several calculators on the internet you can use to get a closer estimate. You put in your tire diameter and axle ratio to get the rpm.
Tom