Komatsu PC40-5 Track Question

Hi all, I have a 88/89 (I think) 40-5 that I'm running into some issues finding tracks for. Komatsu's spec sheets and dealers say the tracks for this machine are 400(mm)x72.5(mm)x70(links). However, the steel tracks I currently have on the machine measure out to be 398.4625x136.525x36. 15.7"x5.375"x36. So, 400x136x36, accounting for stretch. I'm not actually sure how tight the tolerance is for stretch (definitely not enough to get to 136mm from 72.5mm!) but it's possible the pitch is 134mm or 135mm? I just cannot find 400x136 tracks, but I was able to find 400x135 tracks, though with 39 links instead of 36. I did measure pitch from center of pin 1 to the center of pin 5, then divided by 4, and measured center to center of just two pins and got the same number (within a small margin of error). A video I watched said to do it this way, but another I watched said to measure from the outside to the outside. If that's what I should do I can run back out and grab the exact measurements, but that would put the pitch at around 140mm from the outside of pin 1 to the outside of pin 5, divided by 4. In my research I came across a listing for a rubber track that is 400x144x36, but also listed as 400x75.5x74. I'm wondering if there's something similar going on here; as the pitch increases the links decrease for the length to stay the same, so is it possible that the steel tracks Komatsu used to make/put on their machines are just larger than the rubber tracks? Since none of the dealers I spoke with carry steel tracks, and the online listings for DC40-5 steel tracks look right, but either don't list the sizes and just DC40-5/DC40.5, or the specs are 400x72.5Nx74. No idea what the N means, but the 74 links is higher than the links Komatsu says there should be. I'm at a complete loss here, any help or insight will be greatly appreciated.