1969 Bellhousing L78 Camaro Question

[HiHorse]

What is correct for 1969 4-spd 621 bellhousing: "GM" cast on top or "GM" cast on side?

[USER-3965175]

THE 1969 621 BELLHOUSING HAS THE "GM" LOGO CASTED ON THE SIDE UNDER THE THE GM PART NUMBER - SOMETIME DURING THE 1972 MODEL YEAR THE "GM" LOGO WAS MOVED FROM THE SIDE UNDER THE PART NUMBER TO THE TOP OF THE BELLHOUSING AND THE "GM" LOGO REMAINED ON TOP THE HOUSING UNTIL THE 621 WAS REMOVED FROM PRODUCTION SERVICE AT THE END OF THE 1974 MODEL YEAR

M21RSZ28

[NCGuy68]

Interesting..........

How exactly are bellhousings date coded if any?

Thanks for knowledgeable replys.