Most of the comments and/or articles I'm reading now from guys doing that swap are using Astro van clutches.
As I understand it, Astro van clutches come in a couple different diameters with the correct number of splines. Astro van clutches should still be readily available for some time at the parts stores as production on the Astro van started in 1985 and was discontinued about two weeks ago, according to wdoftexas, with the last one rolling off the line at the Baltimore Plant.
