Um, I did have a 9-3/4" clutch and pressure plate on my stock 2.8 and 5 speed - worked fine, no interference. I bought mine from the Fiero Store. I think other people have used up to 9-11/16" clutches with success as well. Haven't heard of a clutch larger than that - perhaps the Archie V8 kits use an even bigger clutch, since the flywheel sits outside the tranny bellhousing within the adaptor plate, but I'll let one of the V8 guys confirm that.
Other than that, yeah stock is 9-1/8" for the V6. Didn't know what the size for the 4 banger was, thanks.
