Thanks for your quick reply cosworthmad. It is only to give a bit of exrtra oomph on the road The engine is actually in a kit car which originally had a turbo so the compression had been lowered with a combustion chambered head. The thing that worried me was that when I looked at the specs the con rod measurements between centres were different with the 1600 being slightly longer. I will follow your suggestion and fit forged pistons, Thanks. John