You weren't using the specs for a Lumina
car were you? The 3.1 in your van is different than the one in the cars. Cars use the vin-T, multiport injection, DIS, etc.. and uses zero-lash rocker arms. Your van uses the vin-D, throttle body injection, distributor, etc.... and uses old style ball and pivot rocker arms. Here is a link to the proper proceedure on your van's engine, and as you can see, there isn't a torque setting for the rocker arms.
http://www.autozone.com/servlet/UiBr...3d801be5e2.jsp