A mid-eighties Astrovan with the four cylinder has the 9-1/8" disk with 1"x14 spline input. Thats the one that I plan to use for my T-5 conversion.
You might check out the placement of the Astrovan shifter. 'Cause on the Astrovans the shifter sits further back than the S-10 trannys. Might interfere with your bench seat......that's if you're using the T-5 tranny from the Astro.
