Yeah the Mahle's are pretty good...German engineering...what piston to bore and ring gaps are you running with them?
I can put my fingers over the rocker breathers after inital run in and gauge when an engine is too loose for street application and wont do the miles. My drag engines breathe a little more but need to due to the high boost and rpm they see and low miles before each teardown.
Red R Racing, Croydon, Racepace, Godzilla Motorsport etc dont use most of the 'Sydneykid thread' crap in their engines to control oil...why? Because its not needed if its built right.
Kat, how much were the pistons out of balance out of the box in your set?