Bolt still stuck solid - had someone in the car this morning holding the brake pedal down and in 5th gear, but everything kept turning, so tried 1st gear which held it a bit better but bolt still would not crack!

Am using a 3 ton trolley jack handle for leverage which is about a metre long.

Has been suggested that I could take out the radiator and intercooler and go for it with my air compressor/impact gun?

Engine was built about 20-30k ago by Harvey Gibbs around 7 years ago.