They install perfectly without making any modification to the engine block as they have the usual 10mm diameter and the usual thread.
They are tested for years on engines over 500 hp super show without any problem and without having to make a new thread cylinder block 12mm threatening to tear it or end up in the water passages having to enlarge the diameter of the cylinder block bores
High traction reinforced head studs for Fiat 500 Abarth engines Fiat Fire or Fiat T-Jet Abarth, Panda 100hp engines and all Fiat fire 8v engines and similar engines.
Reinforced head studs Lancia Delta Fiat COUPE 2000 16V Turbo high traction which ensure correct closure of the head tested up to 530 hp on Lancia Delta engine with usual thread and diameter as standard.