the crank stays with the motor. The 413 industrial is being mated with a np445 4 speed truck box and np203 tcase for my 76 pwagon. my concern is WILL IT SHAKE THE CRAP OUT OF ME?. i want to make sure its properly ballanced before buttoning it up. the industrial came out of a 72 dodge commander rv, the flywheel came from a 76 400 truck, and the tranny and case came from a 75 pwagon