Originally Posted by ChrisGSR
And other non-part-number codes should not be shared across similar-but-incompatible parts. Both the GSR and the Type R belt say "126RU26" on them, in the largest lettering on the belt. Easy to make a mistake.
The LS/RS belt says "125RU26". That reflects good practice. Greatly reduced risk of a mixup with a GSR 126RU26 unit..
lets think about those numbers.
the LS/RS belt is a non-vtec head
the GSR is a VTEC head
the ITR is a VTEC head
in fact the GSR and ITR head are very similiar, and are also probably of a similiar casting. meaning that is why they have the same initial part #
but again ITR definitely has different cams, so i would imagine that small differences between two similiar motors...like cams or cam gears...would translate into a small numerical difference in part numbers.
~boom