No Problem, you're pretty close. Here's the tire application page out of the 1970 Dodge Division Code Guide for Challengers. (Barry, do you have this resource? Mine is a xerox copy. Let me know if you need a copy.) It shows the F60 tire as only being available on the Hemi.


Note: the hand written "OPT" in the 225 column was already there when I got this copy and I haven't verified it's accuracy yet. The booklet is dated Oct 1969, and as you all know, sometimes things change during production.

Tav