Header Gasket Troubles..

Installed Percy's for both at heads and collectors/reducerss on a set of Doug's. Thick flanges for both collector and head, as well as reducers and extensions. Retorqued after some initial run time as instructed, no leaks at all. Have swapped extensions for running at the strip and the reducers on full exhaust countless times. Percy's installed following the instructions, with thick flanges all around and no issues here