The RB 383 were limited to a couple years 59 or until 60 or so. Went is the large body cars that did'nt get the HP motors. Unless one of those builders want it, hey, its a conversation piece if that's what it is. I'm not even sure if that motor came in a 2 brl. Maybe an older thing like the 350, or later a 361. Sure it's a RB?