notes
since i've done this before, here are a few things that i found noteworthy.
width.
you won't find less than 6mm stock. and that's pretty wide. the next up is 9mm, and those won't even fit. when i ordered i had them cut to 4mm. a better ideal is just to have them cut in half to get 3mm and 4.5 mm. perfect. and then you get twice as many. belt corp of america did the cutting for me for nothing. but i can't say that it's their policy. if all of you start ordering and a bunch of cutting they may get irritated. i dunno. try it, and let us know.
pliability.
even though these are the same as what the kits use, mine seemed to be a bit stiff. the backing is thick, and the durometer of the neoprene seemed a bit high. i suspect it is because these belts are typically used for power transmission and/or automation where nobody cares about efficiency, and the belts are tensioned for precise indexing.
now as far as the coding goes...it's usually the actual length that's listed on it. you just divide by the pitch and you'll have your teeth count. if you don't think that it's 3mm, just tip it upside down, and do some math. yes, math. pitch length is...a distance or length. since it is so small, use multiple teeth and divide by them, so as to get better resolution.
measure an arbitrary # of teeth and divide the length between the ends by number of spaces between them. ie, measure from a tooth to another one say 30 away from it. record the distance, and count the teeth including the ends. now divide the distance by ONE LESS than the number of teeth you just counted (that's the # of vallies).
then go look for something that is the same.
glad to hear that this helped or will help you out. of course, post what you know, and this could turn into great tuning thread for the belt cars.