[north]

This is an interesting subject, my 70 Accessorizer is dated February 23rd 1970 and it shows that all GTO tires were G70. Apparently all standard tires on every 1970 GM car were fiberglass belted (in previous years fiberglass belts were extra charge. Also unlike previous years GTO's no longer had redlines as standard (with whitelines no charge option). In the accessorizer it states that the standard GTO tire was the PF blackwall, optional at extra cost was PR white line and PL white letter (white line option not available with Judge option). All three were G70 size. Looking at the 70 Hi perf brochure (dated 9-69) it lists the same standard tire (G70 black) and the same two optional G70 white line and white letter. The full line brochure (dated 9-69) GTO page isn't much use as it only has car illustrations and it shows a GTO convertible with red lines, a GTO hardtop with twin white and a Judge hardtop with white lines. The deluxe full line brochure also has illustrations but different cars with different tires: a GTO hardtop and convertible have redlines and the judge has black walls.

However, I have seen 70 GTO's with original spare G78 twin whites in junkyards.

Similarly some factory documents say the 67 GTO was supposed to have G70 tires as standard