am reading
[email protected] (big font)
with K being KelseyHayes, 1 being the plant. 7 is July
don't see a day of month, maybe it is real close to rh of valve stem.
On font size, the early KH's I've had smaller font XT stamping.
The earliest ive had were Nov '68 dated, they ended up on a real COPO Camaro.
will be shuttling parts early tomorrow will drop you a PM with date of XT's I have.
the latest I've had came of a '70 442.