I have a 500lb scale I borrowed from a friend to weigh my motors. I have a rebuilt 302 with a stock iron heads but alum intake and the scale said 430lbs with 25lbs in balance beam and rigging. It was just the complete engine no alt, no carb, no starter but it did have a flex plate.
I weighed my 351 with the same rigging but my 351 has lighter pistons (J&E) lighter balancer and alum heads and manifold, no flywheel. The scale said 420.
So without the rigging. 351=395lbs ?
302=405lbs
The scale is dead on as it has to be as it is used to test loads for small hoists.
I know that dosen't sound right but that is what I got.
I have pictures of the tests.
Don