Ok, you need to decide what inch you want. Assuming that you'll take the motor .030 over standard to get the cylinder walls clean: a 3.75 stroke crankshaft will make 383, a 3.48 stroke crank will give you a 355. Both of them can run well but the 383 will probably make more power because of the bigger stroke and inch. Also if u build the 383, it is advised to get the spinning assy. balanced before it ever goes into the block. Forged or cast is really up to you. Some say the cast cranks are better for the street because the softer metal allows them to flex a little bit. The forged steel are known to crack because they are so rigid. I'm not quite sure on this however. It really would help to know your budget. Because forged cranks can be 4 to 5 times as much as a cast crank.