Hemicar .. you have a good memory as that was 10 years ago.

B.F. Goodrich 14" Spacesavers were only offered in E-bodies in 1970 and 1971.
15" tires were optional on B-bodies but not optional on E-bodies after 1971.
E-bodies in 72, 73 and 74 carried a full size 14" Goodyear spare in the trunk, no optional spacesaver.