1988 Dodge Raider timing chain reinstallation

I have a 1988 Dodge Raider with a 2.6L that I pulled the head and had it checked out and reworked. I made sure the timing chain did not come off the top sprocket I removed to get the head off. On reinstalling the head, I now can not get the timing chain top sprocket to reach the end of the cam. It is about 1/2 inch too tight. The service manual has no information on this step, it simply says to reinstall the sprocket. I can see from other images there is a timing chain tensioner spring device. What is the trick to "stretch" the chain and get it reinstalled on the end of the cam? The car particulars are a 1988 Dodge Raider (2 door Mitsubishi Montero) with a 2.6L 4 cyc and 175,000 miles.
Thanks very much for the help!