Does anyone know how many input shaft splines there are on 88,89,90,and 91 Si transmissions?

I know my 90 Si had 20 splines, and I just picked up a tranny and it had 21 splines. I believe it's 88-89 but I'm not sure. It pissed me off because I got it right up there and played with it for like 30 mins and it wouldn't go on. Then I counted and I was like oh boy this is bad.

So I'm going to order a new clutch plate and needed to know which clutch plate has 21 splines. Thanks so much!