Consider a mixture of air and gasoline vapor in a cylinder with a piston. (THERMOCHEMISTRY)?

The original volume is 70. cm3. If the combustion of this mixture releases 990. J of energy, to what volume will the gases expand against a constant pressure of 655 torr if all the energy of combustion is converted into work to push back the piston? I would like to have step-by-step guidelines on how to get the answers, but if that's too much work, please tell me the final answers so I can figure out how to work through the problems correctly. Thank you!