273 power? HOW?

I have been giving that some thought also.To change engines and make it look stock.I have my hands on a 340 or a 360 and thinking of putting all my 273 stuff on it or turn my 273 2bbl. to a 4 bbl. car.Either way I would have to rebuild each motor.I guess one of my questions would be is would the motor mounts,balancer,and timing cover from my 273 fit the 340 motor?