Thank you Grantothismo, good diagram, I actually solved the problem by installing shims on the cross shaft between the housing and the spider gears. The spiders were apparently rubbing on the diff housing. Seems the pins on the original gear help to locate the spider gears toward the center of the diff housing as well as hold the shaft in place. I used some small thin washers I had in my parts box. The new steel gears are very smooth now. Thanks to all who replied to this post