The Astro van clutch had 14 splines. Your clutch disc might be from a 1992 Camaro. You can install an 11" clutch with 26 splines if you prefer. I have the info listed on my T5 resource list.
T5 Resource ListFlywheel and Clutch for V8 T5
1980 C10 6.6 L engine = 168 tooth flywheel and 11” clutch disc with 26 splines (V8 Camaro)
1994 V6 Camaro uses a 9.5" clutch disc with 26 splines.
1992 Camaro with the 305ci V8 uses a 10 + 3/8" clutch disc 26 splines.
