tire mfg date?

[bergy]

Good info - when suppliers of big 3 OE tires had to indicate DOT (in the '68 model year per John Z) - they were not mandated to coincidentally add DOT to service replacement tires. So, there was a transition period between '68 and '71 (or '73 in practice) when each supplier of OE tires was mandated to add DOT, but could use their own codes for mfg/date. The universal mfg/date codes were mandated in '71 (or '73). What we're trying to establish is - whether Goodyear abandoned their old (pre '70) date code system and began a new system of their own on the OE tires between '68 and '71 (or '73).

In a nutshell - trying to figure out why the subject tires in this thread have an 8th week of year "9" manufacture date, but the mfg/date code doesn't conform to the federally mandated system post '71 (or '73). Does that imply that the tires were manufactured in 1969 (before the federal mandate went in effect)? Or, did Goodyear fail to comply with the federal system (if the date that these tires were manufactured was 1979)?

If anyone has pics of NOS G70x14 red line tires from '69 or '79 - please post them.

This may seem like a dancing on the head of a pin, but interesting (at least to me) to understand the nuances of manufacturing back then.