If you add in the weight of the back axle, some fuel and the propshaft and gearbox, it probably all balances out and as Martyn says, the V8 is not that heavy. I read somewhere...MGB I think, that the Buick engine was lighter than the B series 4 cylinder!
The points shown in the photo are also used when lifting the car on a hydraulic hoist so I'm sure it is quite well balanced.
