Limited slip installation.

(I may have the title wrong, sure grip or limited slip) One of the many individual parts that I'm working on with my build, is installing a sure grip (limited slip?) in my 8.75. When I got the rear end it had a Dr. Diff spool in it. The ring and pinion are a 4:10.
Both the ring and pinion have very little visible wear. After installing the sure grip I set the rear end up (completely) I.A.W. the factory service manual. Never having experience with (limited slip) sure grip, (only open and locked rear ends and I have the third member on a stand.) I have some questions...How hard should it be to turn the yoke by hand? (It can be turned by hand, but it does require something more than I expected) There seems to be a "dead spot" while turning the yoke. The applied gear marker shows a correct "foot print." Lash properly set with a dial indicator and a correct pre-load on the pinion.
Norm

sure grip.jpg