Engine assembly date could be anywhere from 6 weeks to just a week or sometimes days to the cars SPD. I've had variances in those ranges. Casting dates can be way before assembly dates. Also remember the date on the tag is a scheduled production date so the car may have been actually built on a different day. More confusion to the mix. Rule of thumb, for me anyways, is get within few weeks and good to go.
1959 Bugeye Sprite
1967 Charger Black L code
1967 Coronet R/T Convert Green 440 auto bought from original owner
1968 Charger R/T Bronze 440 4 spd console AM/FM
1969 Super Bee WM21H B5 A40 D21 N96
1969 Barracuda Formula S 340 Convert pilot car
1969 Hemi Road Runner RM23J D32 Omaha orange 4.10 Dana N96 N85
1970 Super Bee WM23N FE5 V1X 3.91 axle package, N96
1970 Road Runner RM21N B3 V1X D13
1971 MG Midget
1971 Road Runner RM23H GW3, A57
1972 Road Runner RM23P FY1, D21
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