Having trouble w/ pinion yoke splines

[sarge]

So I got a few minutes to go out and work on the the 60's yesterday. I pulled the shafts out of the rear and then pulled the diff. and pinion out .... no problem . I start to reassemble with the 4.10 pinion and I can't get the yoke to slip down far enough to get the pinion nut to bite :confused: even stipped out one pinion nut ...... what am I doing wrong ...... I currently have th pinion in the deep freezer and plan on heating the yoke to see if it will help . Spline count is the same so no it's not the wrong yoke or pinion . Last night before grabbing some zzzzz's I pulled the pinion out of the freezer and checked the yoke slippage and it seemed to go on much further . Are the tolerances really that close ???? or am I f'n up something.