On a 2002 buick century 3100 Do you have to take the push rods out to change the lower intake manifold gaskets and if so what is the torque spec for the rocker arms?
You will have to remove the pushrods, and there are two ways to do it. Lisle makes a pushrod tool specifically for 3100 and 3400 gm engines which tips the rockers far enough away from the pushrods so they can be removed, or you can just loosen the rockers up enough until the pushrods are able to come out. I would recommend buying the tool and removing the pushrods that way though because otherwise you will have to loosen and retighten the rocker bolts which have a few different torque specifications. They have revised their specs on rocker torque i think a couple of times, and i have seen a lot of rockers which people have pulled the threads right out when tightening the rockers too hard so if you do take the rockers off, i would take a 3/8 ratchet and get it good and snug. Do not reef on it just get it good and snug. The tool is neat though because it acts as a lever and pulls on the bottom side of the rocker on one side and pushes on the top of the other side and you can pull the pus