Gearbox serial numbers?

[mole42]

I've just collected a replacement 'J'-type gearbox, the gearbox serial number is LD6821, the overdrive is 25/115837/002458

Is there any way to date these parts?
Thanks,

[brig123]

I would say late1973. Usually next to the LD number there is a smaller date stamp. My car built September 1973 is LD 6416 and 13/73 next to it. The o/d is serial 001762. I have a spare box marked LD6979 with 19/73 nearby.

[mole42]

The numbers on mine have "GB" stamped above but I haven't found a date yet!

Gearbox serial number.jpg

[mole42]

I would say late1973.

It's interesting because this is a J-type overdrive 'box and AFAIK they were still using A-type overdrives in 1973.

[trunt]

Parts manual says j type came in at LD21230. The first car built in 73 was 21087