New exhaust cross-over pipe 50's MOPAR

I have a NOS cross-over pipe for the 325 engine. I know it fits a 57 Desoto Firesweep and probably others. The part number on it is 17 ? 6 3 3 50. I can't read the third number if there is one and I think the fourth number is 6. $50 plus shipping from zip code 77379 Thanks, Bill, 713 898-6928