Trouble Installing 18 spline A-833 through dual disc clutch assy.

Thank you all so far. We plan to borrow a real input shaft from a local pal this week to line it all up.
Best we can tell, the fork should be 12" long for an a-body and Ill try to find the pivot distance from center on the stock bell housing and compare it to the aftermarket one.
I hope to hear more from anyone about their experience with the Quick Time housing and the pivot bracket.