Ryan : Based on your Build Date, and the 1960-68 Master Parts Catalog, your Spacer should be a C50Z-8546-A, 3.15" thick, including the pilot (as Jim mentioned). Prior to 11/22/65, it would have been a C20Z-8546-A, 3.22" thick. Interestingly, this same Part Number was also used for 1967 and 1968's with no A/C or TE.
Bob