I have a Classic 4 manual from 1994. It shows 4 rod ends to attach the rudder. Top three rod ends are part number 93004 (3/16" x 10-32 rod end). The 4th (bottom) rod end is part number 93001 (3/16" x 1/4"-28). Bigger than the top three.

Now, in 1996, Old Skystar sent me a revised "Classic IV Fuselage Assembly" (Document P/N 10192.000). This new manual shows only three rod ends to attach the rudder. All three are the bigger part number 93001 (3/16" x 1/4" -28 rod end)

Maybe your rod ends are the wrong part numbers.