Hi can anyone advise what parts i will need to convert an electric compressor to petrol compressor i have the engine already nearly the same rpm so that should be ok
You'll need a pressure sensing throttle valve to control the engines output to match the reciever pressure.
An unloader valve to remove pressure form the pump output and give the engine an easier time when it's reached the desired pressure in the reciever.
Also a blowdown valve that vents the pressure in the ouput lines when the engine is stopped so it has an easier time next time you come to start up.