Does the early chev 350 forged crank have a smaller rear flange than an early 350 cast crank?

Yes, the early Chevrolet 350 forged crankshaft typically has a smaller rear flange compared to the early cast crankshaft. This difference is due to design variations between the two types of cranks, with the forged version being stronger and often used in performance applications. It's important to ensure compatibility with the engine block and other components when swapping cranks.