Change oil every 25 hours.
Check valve lash every 25 hours.
(https://www.eaglersnest.com/forum/gallery/medium_3-291213132539-1152440.png)
On full case engines it will be very hard to get the oil temp up to 160 F unless you keep just
2 Quarts of oil in the case...
To reach full power on the 1/2 it is necessary to reach 1400 F EGT at static RPM...
(https://www.eaglersnest.com/forum/gallery/medium_3-291213132540-1251777.png)