how would you lot put a mount to the engine

Make a crossmember or depending on car use a tube frame front with GRP body work for a competition car.

its 300mm from the side to the engine
adam

Looking at your pictures, would say that the only way would be to make up a crossmember, and mount the engine mounts on that. Fixing them to the thin bodywork would be definately asking for trouble. IMHO. Ray