hi,,putting in a new cam is not a big deal,,the air is your biggest problem,,what caused it to break is the real problem,,dropped valve,,bent pushrod,,bent valve or more likley a valve keeper let go and valve hits top of piston,,.nothing drives off the rear of the camshaft so it could be a bad cam,,,.put air pressure into cylenders?through the plug holes after you remove rocker shafts and that will tell you if you have a bent valve or not,,.if your rebuilding a 360 or a 318 the 440 or 413 is a lot easer in a lt of ways,,.if the oil pressure was good and it did not burn oil ,there is no reason to rebuild the motor,cam and heads can be done in 1 or 2 days depending how fast you are and if you have all the parts ready,,.,also a 440 will run on 4 cylenders very well,,,i drove one from winnepeg to st paul in a 67 gtx,,it acitually got better millage too,,,.220 ci will move a car very well,,if it has to,,go get your car home and pull the intake and the other valve cover and the valley pan undr the intake manifold and turn the engin over with the starter and tell us what you see,,,...plug the gas line and dissconnect the ingtion coil,,,,....rick