Isuzu G-series Twin Cam

Hey everyone,
So I was casually looking at my G180W ZZ/R gearbox today and I noticed a flat section on the passenger side (in front of the cast Isuzu emblem) with some engraved numbers. I was a little confused at this and went to compare it to my other G200W gearbox to which I found the same flat section but it was blank.
I had a quick surf on the net but haven't found any info. Not sure if they mean anything just thought I'd bring it up as an expression of interest.
The numbers are 114, 116, 128 and 129.
Cheers,
Jake

From previous discussions years ago on that issue, no - those numbers have nothing to do with ratios etc. And IMO that's bluddy shame! (As in it's a pity; I don't think Isuzu has anything to be ashamed of, except their Toyota buy-in.)

I wonder if they have to do with casting batch, or type - eg, needle or ball bearing layshaft, or bell size or version.


As to finding ratios, I mount a timing disc on the prop shaft and count its turns and final degree reading after 10 rotations of the input shaft using a white marked clutchplate and then calculate each ratio.
[ I never do 4th, and usually I'll only do 1st, 5th, & maybe Rev. My main interest if 5th - I want the 0.785 or lower versions. ]