I'm a bit worried. i have contacted the seller ."engine builder"
and hope he answer me after the holiday
Ask for referrals from the builder. talk to the owners of these motors. talk to professional engine builders where you are located too.
this is both an engine build philosophy issue as well as a technical question.
lots of opinions from other enthusiasts but they will not be paying your rebuild bill when the motor must be rebuilt.
lifters are now like bearings and piston rings, IMO, as the major internal wear parts in a VW AC hi-po motor.
would you use used bearings in your hi-po vw motor?