replacing intermediate shaft on silverado

I just purchased a new intermediate shaft part#88963611 for my 2000 silverado. I now have a problem. I think the new part does not fit my truck. My truck has a rack and pinion, but the new part seems to be for a circular type of steering. I contacted the dealership which sold me the part and they told me that is the part the techs are installing in the truck. They also told me that no additional parts are used to replace the intermediate shaft. Has anyone installed a new intermediate shaft on their trucks. Need help.