SPID help "S" St. Louis plant

[SS Tim]

Having problems nailing down some information and need some help.
Many plants stopped using the RPO suffix codes on the later production trucks. However some plants continued to use them. Now I know that St.Louis switched to numbers from letters between '71 and '72. What I am trying to nail down is did this happen during the summer of 1971 MY change over, was it earlier or even later? Does anyone have a known original '71 "S" SPID with number suffixes? Does anyone have a known original '72 "S" SPID with letter suffixes?


Also I have a format question as well. So anyone who has an early '72 SPID from "S" St.Louis they will share, I would really like to see it. Ranges from 100001-110001 are best. For those who want to help but prefer not to post a VIN or SPID here is a short term address. Or if you have my normal email please feel free to use that as well.

highdesertdog1969-longhorn@yahoo.com