ZZ,
The mounting bolt holes line-up but you need to ream two of them from their current metric status to allow a 1/2" bolt to go through, but that's not the challenge with these. The transmission input shaft is a little longer than the older stock one, and so is the sleeve around it that is part of the front bearing retainer. Your throwout bearing rides on this sleeve.
Some people cut 1/2" off the input shaft tip to get the trans to slide forward & meet the bellhousing. You need to leave enough of the shaft's tip to allow it to slip into the pilot bearing in the center of the crank. (Make sure you use the one for the trans you're installing as it may have a different internal diameter from the one that's in the end of your crank). Then you cut about 1" off the sleeve to prevent it from interfering with the rotating clutch hub when installed. Note that you need to keep it long enough that your throwout bearing doesn't fall off the end when the pedal is fully depressed.
To make up for the shortening, you then dremmel the input shaft splines back another 1/2" up the shaft to allow the hub to slide that little bit farther up the shaft.
The second way is to make/buy a 1/2" spacer that takes-up the 1/2" gap between an unmodified transmission and the bellhousing & still allows the input shaft bearing retainer to index (read: "center") the transmission into the bellhousing. Do not rely on your mounting bolts as a method of indexing the transmission input shaft to the crankshaft centerline. If you do, you're going to find that the sideways pressure created from misalignment (read: "runout") will soon lead to unwanted transmission noises followed by an eventual failure. So... if the hole in the bellhousing is any bigger than a slip fit for the transmission front bearing retainer, take the two to a machine shop and have an adapter made that aligns them concentrically + or - .001" or buy one from someone who's already been through it.
Once you're that far, you'll need a clutch disc that works. The one on the left is the 11" for a 10 spline shaft out that came out of my
'58 Series 40 Viking with the 235. The one on the right is the 9" for a 1" 14 spline shaft that came from the donor vehicle. All you want is an 11" disc (fits the older 235) with a 14 spline 1" hub (fits the newer trans).
I've heard & read that the '85 Astrovan came with just such an 11" x 14 spline clutch disc. I've also read where some people have had issues with this particular piece and have decided to go with a custom-made clutch. Although a custom disc is not as expensive as you might first think (many driveline shops do them - racers & all that), I'd much rather use something off-the-shelf whenever I can. It makes maintenance & repairs down the road much easier. I will post what my reality is here when I get that far.
FWIW, it looks like either throwout bearing will work for me. I'm going with the older style since it's much beefier.
Edit: The Harbor Freight of Rod Parts, Speedway Motors, offers some concoction of a disc that probably works for a while. I'll shy away from any proprietary stuff for previously mentioned reasons.