D24T.com - HD Clutch

I am amazed to see that anyone is making an aftermarket HD clutch for a diesel Volvo, but it appears that those first two that you linked are indeed meant for a D24 or D24T. I'm judging by the pilot bearing mainly -- those show the correct type needle roller pilot bearing used in the D24 family engines.

Beware the third (stock Sachs) kit though. It may be for a gasser. Again I'm judging by the pilot brg in the photo. Notice how it is much different, a ball-type roller bearing for the gas redblock engine's crankshaft. Some Sachs diesel kits for years have been correct for the diesel application yet come with the wrong gasser-style pilot, so that doesn't necessarily mean the rest of the kit is wrong. But it calls it into question so check part numbers carefully.

With reasonable driving many folks have seen 300,000, 400,000 miles out of stock style Volvo clutches including in diesels, so I wouldn't worry about longevity on the stock clutch in a D24 or stock or even moderately turned up D24T. Power capacity would be the question really that would make you look towards the HD options, IMO. But there can be big, big tradeoffs with higher-capacity clutches in terms of daily driver user-friendliness. Heavier pedal effort, more grabby engagement, sometimes chatter or gear rattle, etc. In other words, with a heavier spec clutch, you are usually *sacrificing* feel and ease of use in exchange for greater capability. Unless you need the extra torque capacity to back up a heavily modified engine IMO the stock setup is usually preferable.