i have a 57 chevy 1/2 ton shortbed project truck,and my dad has a 55 chevy 6400 dump truck. the cabs look real semilar but i want to know if they will swap out,are they the same scale?Or is the 6400 cab larger?I know the fenders are longer and have a bigger wheel well but the cabs look close. NEED SOME HELP ON MAKING A DECISION.