AJ, you can stop typing now because the Passon 18 spline OD is the answer! 2.66:1, 1.59:1, 1.00:1, .80:1 OD. 18 spline! Fits in a regular case!
Comes in 'kit' form for just under $2k or as a built unit for just under $3,200. Pricey? Yes. Solves problems with crummy factory design? Worth...