in the tech section it says that the 87 and later 700r4s came with 30 spline imput shafts and the 86-earlier came with 27 splines, is this correct? i have just heard from numerous sources that the changeover was in 84, and in 87 they just changed the front pump and valvebody etc. is this true? or is it correct that in 86 some 700r4s came with 27 splines?

 

You are correct. The 27 spline input was used to @late'83 production. The aux change over was in '87, although not all have aux in that year so be carefull.