The 85-88 Astro van with the V6 has the larger diameter clutch disc (10.5). The 2.5 liter engine has the smaller diameter clutch.
A T5 hybrid will bolt in without having to cut splines, shorten shafts, etc. (or add a 1/2" spacer)
Steppenwood, they are talking about using the disc, not the whole trans. Also the Astro Van transmission shifter is a bolt-on arrangement moving the shifter over 7" that also comes off when you unbolt it. Standard T-5 otherwise, however much better gear ratios.