This is a GM long shaft water pump with the number 3873830 and GM on the impellor and 118501 and a “T” with a circle around it on the housing. The water pump was on my ’55 Chevy 6 cyl. 235 engine when I bought it. I have been told the numbers do not jive with a ’55 Chevy 235 6 cyl. However, it was working when I removed it to install a short shaft water pump while installing A/C. Buyer pays for shipping.