a903 , a230, a833 , a833od

If you're asking a human being for a clutch, tell them "I have a '71 Duster with a 198 six-cylinder and I need a clutch." (or whatever car/engine you have). If they don't ask you which transmission it has, don't confuse them with information they don't need. If they do ask, no matter what answer you give them, you're going to get the same clutch because only one clutch fits the Slant Six, with the exception of the 10" upgrade (the only difference is the disc, by the way). If they ask what size clutch, and you want the larger one, tell them the 10". If their system delivers a 10.5" clutch which won't fit your flywheel, find a better parts store.

I've been in parts, both dealer and aftermarket, for almost 36 years. You're making this entirely too hard, believe me.

Also, since I don't recall seeing it mentioned, you need to have your flywheel properly resurfaced when installing a new clutch. It will dramatically increase the life of the disc, as well as removing all or most of the heat fractures you will find on the flywheel surface. Don't worry about 'em, don't post on the forums about 'em. They're normal, and if some remain after resurfacing that's normal too. You have a Slant Six, not a nitrous-fed W2 340. Resurface the flywheel and you're good to go.