Which Clutch Kit?

[Ev and the boys]

I have a 168 tooth flywheel (which I will also be replacing), but for some reason had a 10" diameter clutch. In any case, it seems I should be looking for a new 168-tooth neutral balanced flywheel, and an 11" clutch with a 10 tooth 1-1/8" input shaft. Problem is too many choices. Research leads me to seek out Luk brand. However, I'm having trouble finding the part number for it. Doesn't come up on any sites if I use the search "by vehicle." I can find a few part numbers meeting the specs I called out above, and they say "does not fit your vehicle." WTF. Why can't this be easier. Also am I wrong in thinking it doesn't matter which year vehicle you use as long as it has a gen I SBC with the parameters I listed above?