1959-62 Engine Numbers

[otis71]

I know that the sixes and nines on 59-62 FL models used a round back on the year number and a straight back sixes and nines for the sequential numbers. Was there ever a deviation to this? I’ve seen rounded numbers for the sequential number on FL and XL models and wonder if this is a dead giveaway for a restamp?

[BigLakeBob]

My 62 is straight back in the model year and there is one 9 in the serial # which is straight back. Late year high production #, has non drilled outside oil bosses on the heads as well.

[Rioranchopan]

My 62 has straight back in the year as well. Serial number 10xxx. Mike

[otis71]

My concern is rounded sequential numbers

[Architect]

Straight back 9 on my 1959 in the year

[Speeding Big Twin]

Here’s what I’ve found thus far.
In SNs for 59 Pans the year 9 was a certain straight-back type early on but it later changed to a certain round-back type which then seems to have continued for the rest of the 59 model year. The year 5 also changed.
The sequence 6/9 was a certain straight-back type.


In SNs for 60 Pans the year 6 was a certain straight-back type early on but it later changed to a certain round-back type which then seems to have continued for the rest of the 60 model year. The year 0 also changed.
The sequence 6/9 was a certain straight-back type.


In SNs for 61 Pans the year 6 was a certain straight-back type early on but it later changed to a certain round-back type which then seems to have continued for the rest of the 61 model year. The year 1 also changed.
The sequence 6/9 was a certain straight-back type.


In SNs for 62 Pans the year 6 was a certain round-back type early on but it later changed to a certain straight-back type which then seems to have continued for the rest of the 62 model year. The year 2 also changed. NB: both year 2s are different to the sequence 2.
The sequence 6/9 was a certain straight-back type.

I've seen rounded numbers for the sequential number on FL and XL models and wonder if this is a dead giveaway for a restamp?

Can you post partial photos please.

A round-back 6/9 in the sequence portion of any Pan SN (48–65) usually (always?) indicates a problem.

But Sportster SNs seem to have used a round-back 6/9 in the sequence portion for 57–61 models and some, not all, 62 models. And in the year portion for 59–61 models and some, not all, 62 models.

NB: did some 67 Sportster SNs have a round-back 6 in the year portion? I don’t know yet. (A round-back 6 was used in the year portion for some, not all, 67 Shovel SNs and some, not all, 67 Servi-Car SNs.)
Eric