I would tend to go with that. There is no reason for the slight difference in length to cause a great difference in weight between a 302 and a 261. So much is the same or very near the same stuff starter, generator, clutch, flywheel, bell housing, manifolds, cab, distributer, etc. Bigger bore = less cast iron and more aluminum. Bigger journals = less block and more crank. The rods are heavier. By the time you fit it in a car it's not a big difference.
