It is a 904 and will be upgraded to the 727.One transmission repair shop I got has one has a 727 ready to go,he rebuilt it with high performance parts in it.Said it is mine.
My complete early '72 360 4 speed engine cost me $200.00 and is in great shape. There are a couple of mid to 70's running 360 engines for under $150.00 each right now or a decent '79 core to rebuild for $50.00 around here right now.
Any particular reason you want a 727? A 904 with some upgrades will handle anything up to 600hp and quite a bit more with some extra work. A 727 will cost you power to the rear wheels, decrease gas mileage and weigh more. You can also get a wide ratio gear set for a 904 really cheap too and provide a nice increase in torque multiplication. This can allow you to use a gear choice for better gas mileage without a loss of torque when launching your car or increase the torque output when launched for even better performance when compared to a 727.