I agree - great thread - keep the info flowing!!

A66 Challengers recieved E60-15 Polyglas GT tires STANDARD (* early A66 production)
HEMI Challenger R/Ts recieved F60-15 Polyglas GT tires STANDARD

I'd WAG the "delete" wheel lip mouldings was a cost cutting tactic for the A66 package.
Delete the wheel lip mouldings & give the cars a "performance" hood?

Mike, how early in the model year did Creative start modifying HEMI 'Cuda & Challenger R/T fenders?

When did they stop?

HEMI R/T SPD-817 YES wheel lips on b'cast
HEMI R/T SPD-A27 YES wheel lips on b'cast
HEMI R/T SPD-121 no wheel lips on b'cast
HEMI R/T SPD-512 no wheel lips on b'cast