Yep. 20
spline clutch goes with the stepped flywheel. I'm pretty sure most catalogue list the sj413 as the same as sj80.
Clutch industries link to the correct one.
http://catalogue.clutchindustries.com.a ... 9639/R330NI bought an exedy for mine from the states because it was a bargain and I was happy to wait, came with everything too, I don't think you get the antiseize grease for the splines, aligned tools or the pilot bearing with the
clutch industries ones.